Annabel Croft was standing on a clifftop overlooking a sandy beach, her hair blowing all over her face as she addressed the camera.

'Hello,' she said, 'and welcome to another exciting episode of Interceptor. Today we're in North Norfolk, and behind me is the lovely West Runton Beach, where only this year the most complete skeleton of a steppe mammoth, or giant forest mammoth, was discovered.

'With me today are two famous faces: Alvin Seville of the Chipmunks, and Brittany Miller of the Chipettes, and they're going to attempt to meet up within forty minutes to win one thousand pounds for charity. So,' Annabel went on, turning to face Alvin and Brittany, who were standing side by side in their Interceptor contestant costumes and headsets, 'welcome to you both.'

'Thanks, Annabel,' said Alvin, who wore a black costume with a blue waistcoat.

'And thank you for having us,' added Brittany, whose waistcoat was yellow.

'Oh, that's all right,' said Annabel, smiling broadly at them. 'Now, which charity are you trying to win the money for?'

'Well, Annabel,' said Alvin, 'as we're chipmunks, since we've been in the UK we've become very interested in the Woodland Trust.'

'Right, great, that's a brilliant charity,' said Annabel. 'Now, you're going to be blindfolded in a few moments, and then flown by helicopter to your separate start positions, which are about six or seven miles apart. You're then going to talk to me through your headsets, and from your descriptions of where you are, I'll hopefully be able to pinpoint you on my map. Okay?'

'Okay,' Alvin and Brittany both agreed.

'Good,' said Annabel. 'In a moment, you'll both be given one of these backpacks,' and she crouched down beside two open white boxes with black straps that were lying on the ground. 'As you can see, this one contains a thousand pounds in five pound notes – that's your donation to the Woodland Trust – and this other one is empty. Now I'm going to lock them,' and she produced two keys from somewhere about her person, with which she locked the backpacks one at a time, revealing as she closed them five sets of blue, yellow and black concentric circles on each.

'Now then,' Annabel went on, rising to her feet again, 'these keys will be hidden somewhere along your route, so Alvin, you've got to try and find Brittany's key, and Brittany, you've got to try and find Alvin's key. Once you've got your keys, all you've got to do is meet up as fast as possible, open each other's packs, and win the money! Sounds easy, doesn't it?'

'Pretty easy so far, Annabel,' said Brittany.

'What's the catch?' asked Alvin, with a facetious grin at the camera.

'I'm glad you asked me that,' said Annabel, smiling in amusement. 'Your biggest problem today is going to be the Interceptor. He knows your start positions, and he will track you down by helicopter and try to zap the sensors on those packs, determined to lock them permanently and forever. He has an infrared projector on his arm which works rather like a TV remote control, and if he's accurate, it really does work. Now, I'm going to ask you to turn around while I mix up the packs, so you won't know which one of you is carrying the money.'

Alvin and Brittany obligingly turned their backs to Annabel, and she spent several seconds of screen time crouching on the ground, lifting the packs and swapping them over and over. Finally she laid them down flat, stood up again and said, 'Okay, if you'd like to turn round again.'

Alvin and Brittany did so.

'Brittany, which one would you like?' asked Annabel.

'I'll take that one, Annabel,' said Brittany, pointing to the pack that was closer to her.

'All right,' said Annabel, picking up the pack and helping Brittany to put the straps on her shoulders. 'And Alvin, here's yours,' and they went through the same process again.

'Now, listen,' said Annabel, 'various forms of transport will be available to you along the way, so it's up to you to find them, okay?'

'Okay,' said Alvin and Brittany.

'Right,' said Annabel, 'let's go to the helicopter.'

At Felbrigg Hall, a stately home surrounded by greenery, the Interceptor emerged from the arched front porch and swept across the large gravel drive, his long black coat sweeping out behind him. He strode towards a medium-sized black helicopter that was waiting on the grass, its rotor blades already spinning. When he got inside, he began securing himself firmly in his seat with two cross-body straps. He was wearing a headset very like Alvin's and Brittany's, but with larger headphones and microphone.

A small yellow and white helicopter was waiting for Alvin and Brittany. Annabel marched up to it, pulled open the door and said, 'Here you go. I'll get the blindfolds,' and she picked these up from the back seat. 'If you'd like to get in first, Alvin... and Brittany...'

The helicopter was a little high off the ground for the two chipmunks, but Alvin jumped nimbly up to it and then helped Brittany inside.

'Strap yourselves in,' said Annabel, and they did so. 'Right then, you're going to have to put your blindfolds on now. There's yours, Alvin,' handing him a blue scrap of fabric with black trim. 'And yours, Brittany,' a yellow one.

'Right,' said Annabel, once both blindfolds were on, 'you're ready to go. Good luck to both of you.'

'Okay, bye, Annabel,' said Brittany.

'Bye,' said Annabel. 'Have fun.'

She shut the door, then took several steps back, and the helicopter started up. As it took to the air and flew away, Annabel waved enthusiastically to it for quite some seconds, despite having just insisted that its two passengers each put on a blindfold.

'Right, well,' said Annabel, lowering her arm at last and addressing the viewers at home, 'the contestants are off to their start positions, and I'm off to my base in the lovely seaside town of Sheringham. See you in a minute.'

The yellow and white helicopter landed in the middle of a field; the pilot got out and helped Brittany to the ground, where he had to hang onto her arm and steer her away from the tail rotor to stop her from walking right into it. He then led her several feet across the field, where he directed her to hold out her right hand, saying, 'This is Glenn, your cameraman.'

'Hi, Glenn,' said Brittany, blindly shaking Glenn's hand, as the pilot jogged back to the waiting helicopter. He then flew off with Alvin, and took him to a field very similar to Brittany's, where he had to keep him, too, from slicing his head on the tail rotor and introduced him to his cameraman, Andy. The pilot then went back to the helicopter and flew away.

Annabel, meanwhile, was sitting in a pub garden with a large ordnance survey map on the table in front of her, and a view of the sea behind her. She was now wearing a headset, of the larger kind like the Interceptor's, and said into her microphone, 'Right, Brittany, can you hear me?'

'I can hear you, Annabel,' said Brittany, still blindfolded.

'Great,' said Annabel. 'Alvin, can you hear me?'

'Yes, I can, Annabel,' said Alvin.

'Brilliant,' said Annabel. 'I'm going to start with you in a moment, Alvin, when you've taken off your blindfolds. I'll count you down now, okay? Five, four, three, two, one. Okay, start the clock,' and she pushed a button on a stop watch that was on the table beside her.

The very second Annabel started her clock, the Interceptor's helicopter took to the air.

As Alvin took off his blindfold, Annabel said, 'Right, Alvin, describe to me where you are.'

'I'm in the middle of a field,' said Alvin, taking a compass from his pocket and starting to look at it. 'I can see some kind of ruin to the... south of me.'

'A ruin?' said Annabel, her eyes sweeping over her map.

'Yeah, like a castle or something,' said Alvin.

'Can you see anything else?' asked Annabel.

'Just a load of green stuff,' said Alvin. 'There's some woodland north of here... oh, and I just saw a car drive past way down to the south, so there must be some kind of street in front of the ruin. It's running east to west, Annabel.'

'Right,' said Annabel, 'the ruin could be Baconsthorpe Castle. I'm going to try you here,' and she put down a blue plastic figure on her map. 'Yes!' she cried excitedly, as she saw something on the map that the audience couldn't. 'Okay, Alvin, listen to me,' she went on, placing a plastic blue triangle with a picture of a key on it against a cross that had lit up on the map, some considerable distance west of Alvin's start position. 'Your key's quite a long way away at Holt Natural Springs, so I think you're going to have to get a lift.'

'Okay,' said Alvin, beginning to jog along, with Andy the cameraman jogging alongside him. 'I'm heading south toward that street. Oh, the Interceptor's above me!' he added, as the sound and sight of the black helicopter caught his attention.

'Well, don't worry,' said Annabel. 'Just keep your back away from him and he can't get you. Now, if you go down past the castle, you'll get to a small road going more or less south-west, called Hall Lane. If you go down that, it'll come out at a T-junction, which is the road to Holt. You'll need to turn right, and find a lift along that road, okay?'

'Okay, Annabel,' said Alvin, who had been jogging along energetically all the time Annabel was speaking. He was now hopping along in a sideways fashion with his back to the hedge and his eyes on the Interceptor's helicopter, shaking his fist at it. 'Get outta here, man!'

'Where is he, Mikey?' demanded the Interceptor, in his trademark aggressive Scottish accent, looking down from inside the helicopter.

'There he is, Gov,' said Mikey, the helicopter pilot.

'He's tiny!' said the Interceptor. 'How am I supposed to hit what I can't see? Get me closer.'

Mikey took the helicopter as close to Alvin as he could, while the Interceptor opened the door on his left and poked his arm out. When the helicopter was as close as it could get, the Interceptor fired his infrared projector towards Alvin and it gave a short, high electronic sound with each blast.

'Yes!' crowed the Interceptor. 'I got him, Mikey!'

'If you say so, Gov,' said Mikey.

'I do say so,' snapped the Interceptor. 'What, don't you think I got him?'

'Well, you know that better than me, Gov'nor,' said Mikey.

'Damn right I do,' snarled the Interceptor. 'Just fly this thing, Mikey. That's what I pay you for.'

'Yes, Gov, I know. I'm doing it now.'

'Don't get smart with me, Mikey. Take me to the yellow course.'

'Yes, Gov,' said Mikey, and off they went.

'Right, Brittany,' said Annabel, 'describe to me where you are.'

'I'm in a field as well,' said Brittany. She had her compass in her hand, and had got her bearings while Annabel talked to Alvin. 'And I can see a ruin.'

'Another ruin?' said Annabel, frowning down at her map.

'Yeah,' said Brittany. 'There's houses to the west of me, and woods to the north-east. Oh, and a train just went by over there... that must be a railroad to my north.'

'If you're near the railway,' said Annabel, 'it shouldn't be too hard for me to find you. Did you say there's a ruin?'

'Yes, Annabel,' said Brittany.

'Right,' said Annabel, 'the only thing anywhere near the railway that's likely to be a ruin is Beeston Regis Priory, so I'm going to try you there.'

Annabel placed a yellow plastic figure on her map. When the cross denoting the key position lit up, it was very close to the figure.

'Yes, brilliant!' said Annabel, picking up a yellow triangle to place by the cross. 'Brittany, listen, your key's at the Priory Maze and Gardens, which is very near where you are now. You need to go down past the priory to the A149 and turn right, and then this place is just a very short way along.'

'There she is, Gov,' said Mikey, as the helicopter hovered somewhere near Brittany, who was now running down a footpath alongside the priory.

'Yes!' said Interceptor. 'Look, Mikey! Key position!' He had seen a blue and yellow flag not very far away from where Brittany was.

'D'you want me to land, Gov?' said Mikey.

'I'll tell you when to land,' snapped the Interceptor.

'Whatever you say, Gov,ner.'

'I need to get in there and ambush her. Put me down as near the key position as you can.'

'Annabel, there's no sidewalk!' cried Brittany, as she emerged onto the tree-lined A149. Then, as she caught sight of the black helicopter, she squealed, 'Ooh, and the Interceptor's here!'

'Don't worry, Brittany,' said Annabel. 'Just keep your back away from him, and... is there nothing to walk on?'

'Well, there's something,' Brittany realised, and she began jogging along a grass verge, almost falling over a couple of times. 'Aah! It's kind of uneven. Oh, I can see the entrance to this maze and gardens thing!'

'Oh, brilliant!' said Annabel.

The black helicopter landed in a large, open area of greenery, and the Interceptor got out, ducking to keep his head well clear of the rotor blades as he ran towards his target.

'Brittany?' said Annabel. 'How are you getting on?'

'I'm just coming to the end of the parking lot for this maze place,' said Brittany, who was jogging past a few rows of cars towards a small hut. 'I think we need tickets to get in here. Do you have any money, Glenn?' she asked, turning to face the camera.

'Yeah, no worries,' Glenn said faintly.

'Have you got your key yet?' asked Annabel.

'No,' said Brittany, speaking more loudly this time, 'I'm just going into the grounds!'

'You need to look out for a blue and yellow flag,' said Annabel.

'Blue and yellow?' asked Brittany, as though she had never heard the words before.

'A blue and yellow flag,' Annabel repeated. 'That's your key position.'

'Okay. Hi!' said Brittany, coming to a stop as she reached the window of the little hut. 'I need to go in and find a key. Glenn has money for tickets.'

'Oh, you can just go in,' said the lady at the hut window.

'Okay, thanks!' said Brittany, and she jogged to the other side of a short fence which bore the words: Tickets needed beyond this point.

The Interceptor had found his way into the grounds of Beeston Regis Priory Maze and Gardens, and was lurking at the edge of the hedge maze.

'Mikey, where is she?' he asked.

'She'll be there any second, Gov,' Mikey reported from the air. 'You want to get around to the other side of that maze. If you go round it anti-clockwise, you'll be near the exit. She's going to have to go through the maze and come out there.'

'Are you sure about that Mikey?' said the Interceptor, but he was following Mikey's advice even as he questioned it.

'Well, there's an entrance each side,' said Mikey. 'If she retraces her steps, it'll take her much longer to get out again, and you can run round and get her there.'

Alvin, meanwhile, had been jogging along Hall Lane for quite some time. The Interceptor being no longer with him, he was moving in a more natural and comfortable position. Soon enough, he had reached the T-junction that Annabel had promised, and come out onto a much wider but equally verdant road.

'Annabel?' he said. 'I'm turning right here, right?'

'Right, that's right,' said Annabel. 'Now, look out for a lift.'

'Here's a dude,' said Alvin, jogging over to a man who had parked his tractor in a lay-by and was loading some small hay bales onto a trailer that was coupled to it. 'Excuse me, could you give me a ride, please?'

'Where do you want to go?' asked the man.

'Holt Hot Springs,' said Alvin.

The man scratched his head. 'Holt Hot Springs?'

'Oh... I guess there aren't any of those around here,' said Alvin. 'Hold on a second. Annabel?'

'Yes, Alvin?' said Annabel. 'Are you on your way to Holt yet?'

'No, but I'm just about to get a ride,' said Alvin. 'Where exactly do I need to go again?'

'Holt Natural Springs,' said Annabel.

'Thanks,' said Alvin. Then, to the man with the tractor, 'Holt Natural Springs.'

'Yeah, no problem,' said the man. 'Jump up.'

'Thanks,' said Alvin, climbing onto the trailer. He then turned to the camera to ask, 'Are you okay there, Andy?'

'Fine,' Andy's voice came faintly from behind the camera.

'Annabel?' said Alvin. 'This guy's going to give me a ride to Holt Natural Springs.'

'Oh, fantastic,' said Annabel. The man, now in his tractor, started up the engine. 'He needs to go all the way along to the end of this road you're on, and then you need him to take you onto the A148.'

'Okay, Annabel,' said Alvin, not bothering to try and relay this information to the driver, who seemed to know exactly where he was going.

'Right then, Brittany,' said Annabel, clearly satisfied that Alvin didn't need her help for a while. 'I'm just going to find out how you can get to Holt and meet up with Alvin. Um...' Her eyes searched around for a helpful-looking person, and when she thought she had found one, she pulled her headphones away from her ears. 'Excuse me...'

'I can see this exit of yours, Mikey,' said the Interceptor, still walking around the perimeter of the maze. 'I'm going to hide in this thing here,' and he went into a covered area, where he found he could crouch down behind a picnic table. 'Tell me when she's almost out, Mikey.'

'Will do, Gov'nor,' said Mikey.

While Alvin was being driven along on the trailer with the hay, Annabel was having a conversation with the practically inaudible voice of an off-screen civilian.

'A train?' she was saying, still holding her headphones away from her ears. 'Oh, the tourist railway? You mean a steam train? Oh, what brilliant fun!'

Brittany was now inside the hedge maze, where she could see a blue and yellow flag suspended from a pole somewhere deeper in.

'Annabel?' said Brittany.

'Yes, Brittany?' said Annabel, who now had her headphones back against her ears. 'Have you got your key yet?'

'No,' said Brittany, 'but I can see the blue and yellow flag. It's inside the maze.'

' Inside the maze?' said Annabel.

'Yeah,' said Brittany, jogging through a gap in a hedge towards an open wooden structure. 'There's something here to stand on. I'll see if I can figure out how to get to the key.'

'Brittany, listen,' said Annabel. 'When you've got your key, I'm going to get you to meet me in Sheringham and help you get a steam train.'

'A what?' said Brittany. She had now climbed some steps to a wooden viewing platform designed for humans, and was clambering onto the railing to try and get a decent view of the maze layout.

'A steam train,' said Annabel. 'You know, like in the olden days.'

'I didn't know they still had those!' said Brittany, as she hopped down from the viewing platform and started running through the maze. 'Oh no!' she said, coming to a dead end, then having to do an awkward little dance with the camera to get out again, as Glenn needed to stay behind her. 'Okay... okay... this flag thing is just past there...'

Brittany ran alongside the hedge in a U-shape, then found she was at another dead end, but here was the pole from which the key marker flag was flying, and just in front of that, a grotesque figure carved in stone.

'Eww, it's a goblin!' squealed Brittany.

'A goblin?' said Annabel, grinning delightedly, while Alvin chuckled to himself on his trailer.

'It's like a goblin bird bath or something,' said Brittany, for the figure was holding a bowl, though there was no water in it at present. Inside this bowl was the key. Brittany picked it up and said, 'I have the key, Annabel.'

'Oh, brilliant!' said Annabel.

'Way to go, Britt!' added Alvin.

'Okay,' said Brittany, 'how do I get out of this maze? There's some red parts of the hedge here – I think I saw them on the way to the exit while I was up on that platform. I'm pretty sure the Interceptor's around here somewhere, though...'

'She's on her way to the exit now, Gov,' said Mikey. 'Get ready.'

'Good work, Mikey,' the Interceptor said quietly, his head popping up from behind his picnic table.

Brittany was in sight of the maze exit and jogging towards it, looking cautiously about her as she went. She stopped when she reached the gap in the hedge, looked around again, then ventured out and turned to her right. The front of the picnic table hut was level with the line of the hedge here; Brittany walked towards it, still looking carefully all around her, then shrieked and leapt back as she peered into the hut and saw a blond head hovering above one of the tables.

Now that he had been seen, the Interceptor jumped up and came running out of the hut, his coat flying out behind him as he made hawk-like noises and movements.

Brittany screamed bloody murder.

'Are you all right, Brittany?' Annabel asked anxiously.

'The Interceptor's here!' cried Brittany, slamming her back against the outside edge of the maze.

'Well, don't panic,' said Annabel. 'Just keep your back away from him.'

Brittany didn't seem to be listening, at least to Annabel's first piece of advice. Instead she was shrieking hysterically, standing as if glued to the hedge.

Alvin, trundling along on his trailer, was doubled over with laughter.

'It's all right, hen,' said the Interceptor, in falsely syrupy tones, levelling his arm at her as he walked around to her left, trying to get access to her pack. 'I'm not gonna hurt you.'

'Help!' said Brittany. 'Glenn, get behind me!'

Glenn's voice was faintly audible, saying, 'I have to keep the camera on you.'

'What do you mean, you have to keep the camera on me?' Brittany shrieked.

Alvin, still laughing, was able to control his mirth just enough to say, 'He can't interfere because it's journalism, Britt.'

'Oh, shut up!' wailed Brittany.

'Brittany!' said Annabel, giving an amused look to the camera. 'Brittany, calm down!'

At last, Brittany's screams had attracted some attention. A late-middle-aged man who was there with four children came up to her and said, 'Are you all right, love?'

'Quick, stand behind me!' said Brittany, manoeuvring herself in front of him with her back against his legs. 'I have to keep my back away from that guy!'

The Interceptor aimed another zap at her.

'I got you, Mrs!' he said.

'This way!' said Brittany, pushing backwards against the middle-aged man's legs and awkwardly manoeuvring him and herself away from the Interceptor. He followed, and she screamed again.

'Calm down, Brittany!' said Annabel, laughing.

Alvin was in hysterics.

'I'll be back for you, Mrs!' said the Interceptor, as he turned and ran off to another part of the grounds.

'Right, Brittany,' said Annabel, 'has he gone?'

'Yeah... I think so,' said Brittany, looking around, and then finally deciding to step away from the man's legs. 'Okay, thanks,' she said to him, so he went back to his grandchildren. 'What's next, Annabel?'

'You need to get back onto the A149,' said Annabel, 'and keep going along it in the same direction that you were. So turn right again, okay?'

'Okay, Annabel,' said Brittany, who was now getting very out of breath.

'You're going to get to a roundabout,' said Annabel.

'A what?' panted Brittany.

'A circle in the road that all the cars go round. When you get there, you need to turn right again, and then I'm going to meet you on that road, okay?'

'Okay,'

'Alvin,' said Annabel, 'remember you have to turn left at the T-junction, and then stay on the A148 until you get to these springs, okay?'

'Okay,' said Alvin. Then, very dangerously, he stood up and leaned out of the trailer to speak to the driver through the tractor window. A small red car zoomed past them, missing Alvin's head by inches.

The Interceptor was strapping himself back into his seat in the helicopter.

'I got her, Mikey,' he said.

'Are you sure about that, Gov?' said Mikey.

The Interceptor glared at him. 'I got her, all right?'

'All right, Gov, whatever you say.'

'Just fly this thing, Mikey. Take me back to the blue course.'

'Yes, Gov,' and the Interceptor's helicopter took off once again.