Buster, the artificial intelligence that appeared as a red-orange face on a computer screen, announced to the audience, 'Vandal incursion, Kent, 1544. Time Busters, prepare for immediate boarding.'

The computer was on the top deck of a red London bus. Simon, Eleanor, Theodore and Jeanette came running up the stairs, all dressed in black tracksuit trousers and red sweatshirts. They each wore a headset complete with microphone, but Simon and Eleanor also wore red helmets, which obscured the earphones that were visible on Theodore and Jeanette.

'Hi there, TBs,' said Buster.

'Hi,' said the four chipmunks, Jeanette gazing distractedly around the hi-tech bus while the other three looked awkwardly at the game's digital host.

'Right,' said Buster, 'let's have some names to go with the faces. Controllers, please.'

'Theodore Seville,' said Theodore.

There was a moment's silence, then Eleanor poked Jeanette in the back, which triggered her to say, 'Oh! Um... Jeanette Miller.'

'And the eye-cam operators?'

'Eleanor Miller,' said Eleanor.

'Simon Seville,' said Simon.

'Good to have you on board, TBs,' said Buster, as the four chipmunks crowded around his screen. Simon and Eleanor remained standing behind the chairs that had been provided for Theodore and Jeanette. Theodore picked up a clipboard and pen before he sat down; Jeanette sat on hers, stood up suddenly, then managed to sit down again with the items in her hands.

'Right, TBs, we're just outside the grounds of Hever Castle,' Buster told them, 'and it's 1544, which means it's now the residence of Henry VIII's fourth wife, Anne of Cleves, who he divorced in 1540.'

'The same year he married her,' offered Jeanette.

'That's right,' said Buster. 'But they're on good terms, and both of Henry's daughters are staying with Anne at the moment. The trouble is, Dr Paradox is there too, in one of his disguises. It's up to you to find out what his plan is, put a stop to it, then find the time capsule and bring it back here so he'll be stuck in 1544 until one of his time vandals comes to pick him up. That'll stop him from doing any more damage for a while.'

Jeanette looked doubtful about this. 'Can't he come up with a new plan in the same time and place?'

Buster pretended he hadn't heard her and went on, 'The time capsule looks like this.' A monitor in front of the four chipmunks showed a rotating three-dimensional image of a cylinder with a cap at each end. 'When you've found that, TBs, bring it back here so we can neutralise it. Now, I've got some spy-cam footage to give us some idea what's going on. Let's have a look at it, shall we?'

Simon, Eleanor and Theodore all made noises of assent. Jeanette said nothing, busy as she was scribbling on her clipboard, but she looked alert when the spy-cam footage came onto the computer screen. It showed two women in their late twenties, both on a plush sofa in a sitting room that was grandly furnished in the Tudor style. They were watching and listening to a red-haired girl of eleven playing a small harpsichord; she was doing it very well, and when she stood up to show that she had finished, the two women clapped.

'Lady Elizabeth,' said one, in a strong German accent, 'that was most charming.'

'You are coming along very nicely on the virginals, Elizabeth,' said the other woman, who was English.

Elizabeth bobbed a curtsey to each of them in turn. 'Thank you, Lady Anne. Thank you, Mary.'

'Your father will be most proud when next he sees you,' said Anne, smiling as Elizabeth came to sit on the sofa arm beside her. 'He will be impressed by your French and Latin also, I think.'

At this, Elizabeth looked downcast and let out a sigh.

'But Lady Elizabeth!' said Anne, suddenly all concern. 'What is the matter?'

'When will the library be in order again, Lady Anne?' asked Elizabeth. 'I can't find half the books I should like to read.'

'Now, Elizabeth,' Mary said admonishingly, 'you have quite as many books as you need to learn your lessons. It would not be good for you to learn too much else. You will get into a muddle.'

Elizabeth looked at her challengingly. 'Would you say the same thing to our brother?'

'Indeed I would,' said Mary. 'So many things are written that they cannot all be true. It is for wise men, such as our father, to decide what is and is not good to read, for girls and boys.'

'I don't think so,' said Elizabeth, sticking her chin in the air.

'You are only a child,' said Mary.

'Young ladies, please,' Anne said pleasantly. 'Lady Elizabeth, the next time you visit me, you shall have all the books you want.'

'Very well,' Elizabeth said gloomily. 'But what about this time?'

'There is plenty for you to do while we wait,' said Anne. 'Perhaps, this afternoon, you would like to take a walk in the gardens with Mistress Ashley. The flowers are lovely at this time of year.'

'Thank you, Lady Anne,' said Elizabeth, smiling politely but clearly not satisfied.

Here, the footage came to an end.

'Right, TBs,' said Buster, 'what do you think's going on here, then? Who needs our help?'

'Elizabeth,' Eleanor said decidedly. 'Someone's keeping books from her.'

'She said something about the library not being in order,' added Theodore.

'I think you're right, TBs,' said Buster. 'So, what do you think you'd better do first?'

Jeanette was still writing on her clipboard, with Simon looking doubtfully over her shoulder.

'Jeanette,' he said, 'do you think that might be too many ideas? You've practically mapped out Elizabeth's entire life on there.'

'Have I?' said Jeanette, blinking down at her clipboard, then retrieving a sheet she had already flipped over. 'Oh... maybe I have. It's just that so much of Elizabeth's reign was influenced by what she read. I was thinking about all the ways she might do things differently if she was denied access to certain texts.'

'Well,' said Buster, 'the thing is to make sure she can get the books she wants, isn't it?'

'Definitely,' said Simon. 'I think we need to start by finding Elizabeth and talking to her.'

'What about the library?' asked Theodore.

'She can show us where the library is, Theodore,' said Eleanor, 'and maybe tell us what's going on.'

'Right,' said Simon. 'Let's get her perspective first.'

'Sounds like a plan, TBs,' said Buster. 'Where do you think you'll find her?'

All four chipmunks looked blank for a moment, and Eleanor said, 'It didn't sound like they were going to stay in that living room. They could be anywhere by now!'

'Oh, I know!' said Theodore. 'Lady Anne said Elizabeth should take a walk in the gardens. And she probably is doing that because then you can... I mean, it'd make her easier to find, wouldn't it?'

Simon clapped him on the shoulder. 'Good one, Theodore. So...' He looked at Eleanor. 'I guess we'll find her outside somewhere. We'd better get going, hadn't we?'

'I think you better had, TBs,' said Buster. 'We're on a time limit, remember, so... Time Busters, go!'

This was Simon and Eleanor's cue to run back down the stairs, jump from the platform of the bus and go jogging off, over the well-trodden grass, towards Hever Castle.

Task 1: Find Lady Elizabeth.

Simon and Eleanor found themselves running towards Hever Castle, while Jeanette and Theodore watched their progress on the monitor. Hever was a stately home made of brownish-grey brick that had some crenellated towers at the front, giving the impression that it was as castle-like as its name suggested. The building was surrounded by a rectangular moat, which in turn was surrounded by various lawns, trees, hedges and waterways.

'There sure are a lot of gardens here,' said Eleanor, as she and Simon jogged through the verdant castle grounds. 'Hey, Simon, if we're challenged, who should we say we are?'

'Gardeners,' Simon decided.

'What if you're challenged by gardeners?' asked Jeanette, back on the bus.

Simon frowned in thought. 'Stable boy and girl? They must have some horses around here.'

'Look, Simon,' said Eleanor, as they rounded a corner and saw the Lady Elizabeth walking among some trees, chaperoned by a grown-up woman. 'There's Elizabeth.'

They jogged over to her. The woman looked up at the sound of their approach, and frowned at them.

'Don't you know better than to approach her Ladyship uninvited?' she asked.

'Sorry,' said Eleanor, 'but we just wanted to talk to her about the missing books.'

'The missing books?' This got Elizabeth's attention. 'It's all right, Kat. They must be novices belonging to Bishop Morgan and Father Robert. Is that right?' she asked them.

'Um... yes,' said Simon, looking peeved at not being able to use his own idea.

'Strange-looking novices,' muttered Kat, stepping back from the two chipmunks as Elizabeth stepped forward.

'Do you know what is happening to the books?' asked Elizabeth. 'Are they being stored somewhere until the work in the library is finished?'

'Work in the library?' said Eleanor. 'Oh, yes... the work in the library. We'd heard something about that, but we're a little hazy on the details. Aren't we, Simon?'

'Yes, we are,' said Simon. 'We only arrived today, you see.'

'But you must have been sent to assist Father Robert with his task,' said Elizabeth. 'Didn't anyone explain things to you?'

'No,' said Simon. 'Too busy. You know how monasteries and nunneries are.'

'Well,' said Elizabeth, seemingly not interested in Simon's small talk, 'when the Lady Anne talked of somebody cataloguing the library, Mary thought a priest might be the best choice. She said something about checking for unsuitable texts... she meant religious texts, of course.' Elizabeth's smile had vanished by the time she said this, and she looked instead like she was smelling sour milk. 'Though I don't think they'll find any texts my father wouldn't approve of here.'

'Yeah, there is no way,' Eleanor agreed with her. 'So... this Bishop Morgan and Father Robert are cataloguing the library, and books have been going missing?'

'Yes,' said Elizabeth, 'and not just religious books, either. I was particularly wanting to read the works of Cicero yesterday afternoon, but they are simply nowhere to be found.'

'Did you ask one of these priests about it?' asked Eleanor.

'I asked Father Robert,' said Elizabeth, 'and he said I was welcome to look among the books piled up all over the library. He probably thought I would change my mind then, but of course I didn't.'

'Of course,' Simon agreed. 'So, I guess we'd better go see what's happening, hadn't we? Maybe we can find those books for you.'

'It would be marvellous if you could,' said Elizabeth. 'If you were to recover Cicero for me, I should think I'd be grateful enough to give you a reward.'

'We'll do our best, Lady Elizabeth,' said Eleanor. 'Do you think maybe you could point us toward the library? And... maybe get us into the castle? I don't mean to speak out of turn, but those guards over there don't know us, you see.'

'Yes, all right,' said Elizabeth. 'We'd better go now, while Kat is distracted. Look, that's Bishop Morgan she's talking to over there.'

Simon and Eleanor looked, and saw that Kat's attention was indeed being held by a priest who wore a purple robe and mitre.

'Hmm...' said Simon, furrowing his brow in thought. 'I think we'd better get out of here, Eleanor.'

'Follow me, then,' said Elizabeth, and she began leading them to the front of the castle. She set a fairly fast pace, for which a surreptitious glance at Kat seemed to suggest the reason.

Task 2: Find the library.

'Good job, you guys,' said Theodore, as they walked briskly along. 'So... what's going on here? Some priests are hiding books from Lady Elizabeth?'

'That's right,' Buster agreed. 'According to my data banks, TBs, Cicero's work was a huge influence on Elizabeth I's ideas about public speaking and government ethics. Can you imagine what her reign will be like if she never gets to read it?'

'Hmm...' said Jeanette. 'That would take some thinking about.'

'Don't worry, Buster,' said Theodore. 'We'll make sure she gets all her books back.'

Simon and Eleanor, meanwhile, had crossed the drawbridge, passed two guards at the door and entered the castle with Elizabeth. They were standing in a large hallway, and she was pointing towards a door on the right.

'The library is just there,' she said. 'Now, I must get back to Mistress Ashley. With any luck, she hasn't started to miss me yet. Goodbye!'

'Bye!' Simon and Eleanor said distractedly, already jogging with squeaky shoes across the ornate wooden floor to the library. As soon as they reached the door, voices could be heard, and when they went inside, they found Mary speaking to a young priest among piles and piles of leather-bound books.

'If you find any Lutheran texts,' Mary was saying, 'just dispose of them quietly. It will have been the Boleyns who put it there, and we don't want the Lady Anne getting into any bother over it. Nor do we want the Lady Elizabeth upset. Her mother's name is tarnished enough.'

'I understood the Lady Anne to be a Lutheran herself, Your Highness,' said the priest.

Mary raised her chin. 'She is an excellent woman who was raised among heretics. That is all the more reason to keep evil things out of her way.'

The priest bowed his head. 'Yes, Princess, of course. Your word is my command.'

Jeanette said from the bus, 'He shouldn't be calling her "Princess" and "Your Highness". Not since Henry's marriage to Katherine of Aragon was annulled.'

'Hadn't you guys better do something now?' asked Theodore.

'I don't really feel like we can interrupt,' Simon said quietly, speaking into his microphone out of the corner of his mouth, but Mary seemed to have finished with the priest anyway.

'Good day, Father Robert,' she said, then turned and saw the two chipmunks in helmets, sweatshirts, jogging trousers and trainers. She stared at them. 'Who on God's green earth are you?'

'Novices,' Eleanor said at once. 'We've been sent by Bishop... oh, um...'

'Morgan,' said Theodore, looking at his clipboard.

'Bishop Morgan,' Eleanor finished, with a placating smile.

'Really?' Mary said archly. 'Is this how they are dressing novices nowadays? What are things coming to?'

'Oh, it's just something they're trying out,' said Eleanor. 'They'll have probably decided against it by this time next week.'

'I certainly hope so,' said Mary, and she stalked from the room.

Simon and Eleanor approached Father Robert.

'Need any help, Father?' asked Simon.

Father Robert looked harangued. 'Well, I don't know... I've got quite specific instructions from the Bishop, and now from Princess... from Lady Mary,' he amended, looking awkwardly at the two chipmunks.

'Just a slip of the tongue, I'm sure,' said Simon.

'Of course, of course,' said Father Robert, now flustered as well as harangued. 'The Church of England ruled her mother's marriage invalid. That makes it so.'

'It's okay, Father,' said Eleanor. 'We won't tell anybody about any... slips of the tongue.'

'I'm confused,' said Theodore, providing a somewhat unnecessary distraction in Simon and Eleanor's ears. 'If England isn't Catholic now, why is anybody going to get in trouble over these Lithuanian texts?'

Simon attempted the ambitious feat of answering Theodore's question and getting on with the game at the same time. He said to Father Robert, 'I suppose the Lady Mary's right to tell you to get rid of any Lutheran texts you find, since the only real change Henry wants is to be head of the Church himself. Has she asked you to remove anything else? Maybe we could help.'

Father Robert looked a little baffled by this long speech, while Theodore, on the bus, looked even more confused than before.

'The Lady Mary only wants me to remove heretical texts,' said Father Robert, 'and rightly so, but I don't expect to find any. Goodness me, if I do, there might be no books left at all by the time I've finished!'

Simon and Eleanor exchanged a look. On the bus, Jeanette and Theodore looked alert.

'What do you mean?' asked Simon.

'I have orders from Bishop Morgan to remove certain classical texts,' said Father Robert.

'You mean like Cicero?' asked Simon.

'Funny you should mention Cicero,' said Father Robert. 'I found a lot of his volumes only yesterday. The Bishop said I was to burn them, but... well, I just couldn't do it. I'm a scholar myself, you see.'

'Good on you, Father,' said Simon. 'So, you've hidden a stack of classical scholars somewhere around here?'

'Where?' Eleanor asked eagerly.

Father Robert looked cagey. 'That's not for novices to know. I'm planning on telling the Bishop about it later, and suggesting we take them somewhere they can be of use.'

'Good plan,' Simon said approvingly.

'Unless it turns out they're wanted here,' Eleanor added hastily.

'Oh... yes, of course,' said Simon. 'For the ladies to read.'

Father Robert shrugged and got back to his work, sorting through the books. 'You know I take my orders from the Bishop, and so do you two youngsters.'

'What does the Lady Anne think of all this?' asked Eleanor.

'She has not spoken to me about it,' said Father Robert. 'It is for the Bishop to take instructions from her.'

'Okay,' said Simon, edging towards the door. 'Well, if you don't need any help, I guess we'll just get out of your hair.'

'Okay!' said Eleanor, once she and Simon were out of the library. 'Plan of action. There's one person around here who can definitely overrule this Bishop Morgan character, and that's the Lady Anne.'

Task 3: Find Anne of Cleves.

'But we don't have a clue where she is,' said Theodore.

'We'd better try asking someone,' said Eleanor, setting off at a jog, with Simon close behind her. They headed for the front door and back out to the grounds, where they saw Elizabeth in the distance, still being looked after by Kat Ashley.

'Perfect!' said Eleanor. 'Elizabeth'll be pleased with us now, and maybe she can tell us where Anne is. Lady Elizabeth!'

Eleanor began running and waving, with Simon jogging along behind her. Elizabeth turned to them with a smile, and Kat with a frown.

'We've found out what's happening to those books you want,' said Eleanor, 'but we don't know where they are now. We're looking for the Lady Anne, so she can tell the priests to put the books back in the library.'

'You mean Father Robert's deliberately removing them?' asked Elizabeth, shocked.

Eleanor nodded. 'On the orders of the Bishop.'

Elizabeth frowned. 'I thought something wasn't right about that Bishop Morgan fellow.'

'Do you know where we can find the Lady Anne?' asked Simon.

'Yes, I do,' said Elizabeth. 'She and some of her ladies are walking in the maze. It's just over there,' and she pointed.

'Thank you,' said Eleanor, and she and Simon went jogging off towards the hedge maze.

'Was that a maze she was pointing to?' asked Theodore.

'That's right, Theodorable,' said Eleanor affectionately.

'Well, don't get lost!' said Theodore.

'We'll do our best, Theo,' said Simon, entering the maze, with Eleanor just behind him. 'We aren't even trying to find the middle, are we? We're just looking for a person. So... I guess we just run around until we find her.'

He and Eleanor jogged around between the high hedges for a minute or more, occasionally coming to a dead end and having to retrace their steps. Eventually, the sound of women's voices could be heard talking and laughing, one in a strong German accent. Simon and Eleanor began running towards the voices.

'We can see Anne,' said Eleanor.

'Oh, good,' said Jeanette. 'What are you going to say to her?'

'That Bishop Morgan has told Father Robert to take out some of the books, of course,' said Simon.

'You could remind her that Lady Elizabeth was looking for them,' said Jeanette.

'Good idea, Jeanette,' said Simon, as they came close to Anne and two of her ladies, as well as two small spaniels whom Anne was holding on leads. When the two chipmunks came running up to them, the dogs began barking and jumping excitedly.

'Excuse us, Lady Anne,' said Eleanor, executing a bob curtsey, and pulling Simon down into a bow. This interested the spaniels very much, and they started jumping up close to Simon's face.

'Good heavens!' said Anne. 'Children! Do I know you?'

'No, my Lady,' said Eleanor. 'We're a novice nun and monk. We were sent to help Father Robert.'

'Ah, Father Robert,' said Anne, smiling. 'He is a very good man.'

'Yes, very,' said Eleanor, while Simon tried to fend off a frantic licking from the two dogs.

'Tell her about the books!' Theodore squealed into his microphone.

'He's doing a very thorough job in your library,' Eleanor went on, 'but we thought we ought to ask you if it's okay for him to take away some of the books. He says Bishop Morgan told him he was supposed to.'

'Ach! Can it be?' said Anne, astonished. 'I gave him no such instructions. Are you sure about this, children?'

'Tell her about Elizabeth!' squeaked Theodore, causing Simon to wince in discomfort.

'Not so loud, Theodore,' he said, pushing an excited spaniel away from his face.

'We've heard that the Lady Elizabeth was looking for some books,' said Eleanor. 'One of them was Cicero, wasn't it? Father Robert said something about being told to get rid of Cicero.'

Anne's open and friendly face fell into a frown. 'This is not what I have asked the Bishop to do. I will have a word with him. Here, Lady Catherine, take the dogs,' and she handed the two leads to one of her ladies. The dogs were yanked away from Simon, and he stepped back to put a greater distance between them and himself.

'Okay,' said Eleanor, as Anne walked purposefully away, 'so... I guess we'd better get out of here now.'

She and Simon began making their way out of the maze, while Theodore and Jeanette flicked through their clipboard pages.

'What should we tell them to do next?' asked Theodore. 'We don't have any more leads.'

'We're supposed to find this capsule thing, aren't we?' said Jeanette. 'How are we supposed to know where it is?'

'Some good questions, TBs,' said Buster, making his presence known for the first time in quite a while. 'One of my spy-cams is picking up an interesting conversation in the library just now. Lower your visors and we'll have a look, shall we?'

Simon and Eleanor, having just emerged from the maze, obediently lowered the visors on their helmets. Jeanette and Theodore watched their monitor with pens poised.

The scene showed Father Robert in the library once again, this time with the purple-clad man they had only seen at a distance, when he was talking to Kat Ashley.

'Were they indeed?' he was saying, looking peeved at whatever Father Robert had just told him. 'I happened to hear from Mistress Ashley that there were two novices here. She pointed them out to me in the garden. But I can assure you, I didn't send for them. I hope you didn't tell them anything, Father Robert. They obviously aren't trustworthy.'

'I am only cataloguing a library, my Lord,' said Father Robert. 'What is there to tell?'

'But you aren't only cataloguing it,' said Bishop Morgan. 'Did you tell them about the books I told you to remove?'

Father Robert looked uncomfortable. 'I suppose I might have mentioned it. Why, was it a secret? I don't think I'd better be doing it, if it isn't on Lady Anne's orders.'

'You are right there, Father,' came a familiar, accented voice from some distance away.

'You fool!' Bishop Morgan hissed at Father Robert, to the sound of approaching footsteps. 'Just be careful what else you say. And remember not to go poking about in the chapel. I haven't finished straightening it out yet.'

'Bishop Morgan!' said Anne, stepping into the camera shot. 'A word with you, my Lord Bishop, if you would be so kind.'

Bishop Morgan smiled obsequiously at Anne, and walked out of shot with her. Father Robert turned back to his work. The video ended, and Simon and Eleanor lifted their visors.

'Right, TBs,' said Buster, 'what does that tell us?'

'Well,' said Eleanor, 'Bishop Morgan is definitely Dr Paradox.'

'And I think we know where the time capsule is,' said Theodore. 'In the chapel!'

'It'd better be,' said Simon, 'or we still don't have a clue. But where is the chapel?'

'You'd better find out,' said Theodore. 'Just... I don't know... ask someone?'

'Ask Mary, if you see her,' said Jeanette. 'If you tell her you want to pray there, she'll be only too happy to help. She'll probably think you're Catholics.'

Task 4: Find the chapel.

'Good thinking, Jeanette,' said Simon, as he and Eleanor went jogging off again.

Theodore looked at Jeanette. 'Why will Mary think they're Catholics if they say that?'

'Because Catholics believe you can't pray just anywhere,' said Jeanette. 'Mary will approve of them wanting to use the chapel, where there'll be statues and stuff to kneel in front of.'

'Does King Henry think you can pray just anywhere,' said Theodore, 'or is praying in chapels one of the Catholic things he actually wants to keep?'

Jeanette furrowed her brow. 'I'm not sure. He's published an English Bible that people can read at home, and he's confiscated all the idols from the churches and abbeys, so maybe he does think you can pray anywhere.'

'I feel kind of bad, lying to Mary about this stuff,' said Eleanor, as she jogged along through the castle grounds.

'It's okay, Eleanor,' said Simon. 'Remember, it's all in the name of charity.'

'Oh, I was forgetting that,' said Jeanette. 'You know, I don't really see how winning this game can –'

'Any sign of Mary yet, TBs?' Buster interrupted.

'No,' said Simon, panting a little now, 'but we're heading for the castle because that's where we last saw her.'

'Oh,' said Eleanor, also beginning to get out of breath, 'that's why! I wondered if you knew where you were going, Simon.'

'Of course I do,' said Simon, as they jogged over the drawbridge and approached the two guards whom Elizabeth had helped them pass earlier. He asked them, 'Has the Lady Mary left the castle?'

Both guards shook their heads, so Simon and Eleanor carried on into the building. They poked their heads into a few rooms, including the library, which was still full of piles of books but now bereft of people. As they were leaving this room, Eleanor noticed something, tapped Simon on the arm and said, 'Look, stairs. Shall we try going up them?'

'What have we got to lose?' said Simon, and they went up the stairs. At the top, walking along the gallery, was Mary.

'Ooh, Mary!' called Eleanor, waving. 'I mean... my Lady!'

Mary looked sharply at them, and raised her eyebrows as they approached her.

'We're looking for the chapel,' said Simon, but this seemed only to make Mary more suspicious of them, judging by her face.

'We want to pray,' added Eleanor, blushing slightly and looking away. 'Can you tell us where it is?'

Mary's expression softened. 'But of course. I've just come from there myself. If you walk to the end of this gallery, then turn right, you'll find the corridor that leads to the chapel.'

'Thank you,' said Simon, then he and Eleanor jogged off along the gallery.

'You've got less than four minutes left, TBs,' Buster announced out of nowhere.

'Oh, the time limit!' panted Eleanor. 'I'd totally forgotten!'

'Why is there a time limit?' Jeanette asked vaguely, as Simon and Eleanor rounded a corner into the chapel.

'Quick!' yelled Theodore. 'Find the time capsule and get out of there!'

Task 5: Retrieve the time capsule.

The chapel was a small room lit by stained glass windows depicting religious scenes, three on the back wall and two on the side. Against the back wall was a table covered with a red velvet cloth, on which sat a large Bible. Opposite the two windows, on the other side wall, was an altar with candles and a standing crucifix. On the wall above this hung a picture of the Virgin Mary.

'Well, there aren't many places it could he in here,' remarked Simon, lifting up the altar cloth, while Eleanor lifted the red velvet and then had a flick through the Bible. 'It doesn't exactly need much "straightening out", Eleanor, does it?'

'I bet they didn't even have that expression in Tudor times,' said Eleanor. 'The time capsule's not over here, though.'

'It's okay, I've got it,' said Simon, retrieving his hand from underneath the altar cloth to reveal that he was now clutching the vital plastic cylinder. 'So, let's go! Three minutes or so should be plenty of time to get back to the –'

'Finished already?' said Elizabeth, stopping Simon and Eleanor in their tracks as they ran from the chapel. She stood smiling broadly at them, her hands held down in front of her and clasping a book. 'Mary said you were here. I didn't want to interrupt you at prayer.'

'Well, actually,' said Simon, 'we've just remembered we have to be somewhere urgently. So, if you wouldn't mind...'

'My Lady,' Eleanor added hastily.

'In just a moment,' said Elizabeth. 'I can't let you go without thanking you for finding out what was happening to the books. Lady Anne ordered Bishop Morgan to put them all back, and she told Father Robert to give me Cicero straight away. And see, here he is,' she said, her smile broadening as she held out the precious volume.

'Oh, good,' said Eleanor, through a forced smile, jiggling impatiently on her feet.

'As a token of my thanks,' Elizabeth went on, 'I wish you to have this.' She slipped a ring from her finger (no easy task with a large book in her hands), and held it out to the two chipmunks.

Simon took the ring and slipped it into his trouser pocket. 'Thank you. Goodbye,' and he barged past Elizabeth, running as fast as he could, with Eleanor close behind him.

They ran down the stairs, and were almost at the front door when Dr Paradox, still dressed as Bishop Morgan, appeared in the library doorway. He caught sight of the red sweatshirts, growled, 'Time Busters!' and took off after them, his purple robe billowing out behind him and his mitre falling off somewhere between the library door and the drawbridge. 'Drop that capsule!'

'Less than a minute to go, TBs!' said Buster.

Simon and Eleanor kept running, with Dr Paradox chasing them and calling out commands to them to stop.

'Don't listen to him, you guys!' yelled Theodore.

'We weren't planning to, Theodore,' panted Simon.

'Silly of him to bother with yelling, really,' said Jeanette.

Simon and Eleanor reached the bus and jumped on board; Simon took the time capsule upstairs, with Eleanor still behind him, and secured it in a pair of time capsule-sized claws on the computer console.

'Well done, TBs,' said Buster. 'That should keep Dr Paradox here for at least a fortnight.'

'Is that how long it takes his time vandals to find him?' asked Jeanette.

'Yes, about that,' Buster said dismissively. 'And you got something else back there, didn't you, TBs? What was it the Princess Elizabeth gave you?'

'Lady,' said Jeanette, 'not Princess. Her mother's marriage was annulled too, remember.'

'It was this,' said Simon, producing Elizabeth's ring from his pocket.

'Wow,' said Buster. 'That must be worth a few quid. What are you going to do with it, TBs?'

'I think,' said Eleanor, exchanging a knowing smile with Theodore as she went through the pre-planned conversation, 'we'd better donate it to an appropriate charity. What about English Heritage, you guys?'

'Ooh, good idea!' said Theodore. 'They take care of old castles and stuff in our time, don't they?'

'An excellent and highly appropriate cause,' said Simon. 'I agree with your suggestion, Eleanor.'

'A ring that really belonged to Queen Elizabeth I as a child must be worth a fortune,' said Jeanette.

'Well,' said Eleanor, looking confusedly at her sister, 'I guess... when they sell it... they won't be able to prove it belonged to her?' There was a question mark in her voice as she tried to maintain the televisual illusion.

'Probably not,' Buster agreed. 'I'd estimate, in your time, that should fetch them around five hundred British pounds. And most importantly, Elizabeth's still on track to become the queen we all know, and bring about her Golden Age. Thanks for your help, TBs.'

'Oh, it was nothing,' Theodore said modestly.

'It was fun,' said Eleanor.

'Most educational,' added Simon, and Jeanette nodded in agreement.

'Right,' said Buster, 'we'd better get you all – and that charity donation – back to your own time,' and with that, the large red bus disappeared from Hever Castle car park.