The double wrath of Peleus' son to tell –

Divine Achilles, mightiest man at Troy:

His sloth, while many heroes fought and fell,

And how at last he rode out to destroy,

But, though he won, it gave him little joy,

Sing, heavenly Muse! I cannot but by you

Tell how his feud with Agamemnon grew.

Homer, The Iliad

Troilus son of Priam took the ibex-horn bow in one hand, and the arrow in the other. It had a flint arrow-head, not because the Trojans didn't know how to work metal, but because a flint tip that could flake off into the victim's wound, leading to infection, could cause more trouble than any amount of metal.

It was Troilus's last arrow, and he'd been shooting all morning without success. This is my last chance, he told himself, trying to remember all the things you had to do when shooting. Keep the target in sight – check. Fit the arrow to the bowstring – check. Pray to Apollo the god of archery, promising him a rich sacrifice of firstborn lambs – well, there was a war on, and meat was scarce, but perhaps Troilus's father would let him have a pigeon to sacrifice, if he achieved glory today. Draw the string back until the bow forms a circle – tricky, as Troilus was only ten years old, and trying to fire a man-size bow that he'd borrowed from a friend. This wasn't at all like playing with his toy bow made from a piece of stick. But he had to prove he was a man. After all, it was his brother Paris's girlfriend they were fighting over, and Hector and all his other brothers were fighting to defend the city, and if Troilus could only prove he was a hero beyond his years, maybe he could learn to drive a chariot and fight with a spear as well. Everything depended on this moment. Troilus squinted along the arrow, lining it up with the target, pulled it back as far as he could, and let go. The arrow arced through the air, and dived into the dust of the palace garden, just short of the straw-filled sack with a series of rings chalked on it.

The owner of the bow walked over to the sack, moved it a few feet closer, and began collecting the scattered arrows. 'You're definitely getting the hang of it,' he said kindly. 'Only you need to allow for wind direction. But yep, a bit more practice, and sacks of straw all over the battlefield will be fainting at the sound of your name.'

Troilus laughed. 'What's it like shooting – well, things that aren't sacks of straw?' he asked. 'Do you have to ask your friends to put their shields in front of you so that the enemy doesn't shoot you first?'

'Uh, not exactly,' said the archer, whose name was Pandarus son of Lycaon.

'Have you ever been wounded?'

'No, well, what I usually do is to hide in a thicket so that the enemy doesn't charge at me with its horns down, shouting "Baaa!" I used to go hunting for wild goats a lot, you see. That's how I got this bow, in fact.'

Troilus considered this. 'How did you catch the goat before you made the bow out of its horns?'

'I said I was hunting for wild goats, I didn't say I caught one. But I used to be really good-looking – this was when I was about sixteen or seventeen – and while I was crouching in a thicket waiting to ambush a goat, the god Apollo appeared to me and gave me this beautiful ibex-horn bow with gold string-hooks, and then he asked me to kiss him. And I said no thanks, he wasn't my type, and he flew into a rage and put a curse on me that no girl I fancied would ever be interested in me, and that's why I haven't got a girlfriend.'

'Who'd want a girlfriend?' snorted Troilus. 'I'd rather have a bow like this any day. Can I have another go at firing it?'

'Later. Your mum's calling you in for lunch now, and anyway I need to get some archery practice in myself. Your brother Hector's planning to fight the Greeks the day after tomorrow. Go on in and have your lunch, you're a growing lad, you can't afford to miss meals.'

Troilus disappeared into the palace, and emerged a few minutes later with a plate of sandwiches. 'Mum says I can have my lunch outside as long as I'm not a nuisance to you when you're training,' he said. 'D'you want a sandwich?'

'I'm not hungry, thanks. That's one thing about being in love: it's the ultimate slimming diet.'

'I'm not ever going to fall in love, then,' said Troilus, helping himself to a sandwich. 'It's silly, getting all soppy about girls, the way Paris is about Helen. And that's why we're having this war, isn't it? Because all the Greeks were in love with Helen, so they've got into a thousand ships and come to attack us, so you and King Sarpedon of Lycia and all the other Turkish kings have all brought armies to protect us because you think Helen's pretty too, haven't you? Hector wants to get married to a lady called Andromache, and she's nice, but she's not as pretty as Helen. I don't think anybody would launch a thousand ships for Andromache. Maybe they'd launch a couple of canoes and a dinghy for her. But when I said that to Hector, he said I was a silly little kid who didn't know what I was talking about.'

'Well, you don't,' said Pandarus. 'And you especially don't know about not offending gods like laughter-loving Aphrodite, and her son Eros. Because if you go round laughing at grown-ups for falling in love, Aphrodite will laugh at you, and say, "In time, the savage bull doth bear the yoke," and tell Eros to shoot you and make you fall up to your eyebrows in love with someone, so you spend your nights tossing and turning and not being able to sleep, and your days writing love sonnets that you're too shy to give to the girl you love.'

'Do you do that?'

'Of course. It happens to everyone.'

'Who are you in love with?'

'"Nay, niver arsk me that, King Priam's chile. My secret mun go wi' me to my grave,"' said Pandarus, in a silly voice, like a crazed old peasant, which made Troilus laugh.

'It's not my sister Cassandra, is it? I don't think she likes you, but maybe she's just pretending because she's too shy to tell you she's in love with you. But she says you're louche and you're a bad influence on me and dad shouldn't be letting you sleep in my bedroom. That's just what Cassandra says,' Troilus added hastily. 'I like sharing my room with you. It's good when you tell me stories. What does louche mean?'

Pandarus shrugged. 'I don't know, maybe "like a wolf" or something? But I like sharing with you, too,' said Pandarus. 'It's like having a brother.'

'Huh, having brothers isn't much fun!' said Troilus. 'Well, Deiphobus is all right, and Hector's quite nice for a grown-up, but Paris is a real show-off. And altogether I've got forty-nine brothers, and fifty sisters, because my dad's got loads of girlfriends as well as mum, and they all keep arguing all the time.'

'I suppose you're right,' said Pandarus. 'There's an old proverb in Zeleia, where I come from: "A friend loves at all times, and a brother is made for adversity." So maybe we're better off being friends and sworn brothers than actual biological brothers.'

'Have you got any brothers and sisters?'

'No. I used to have a big sister called Argive, and she was lovely. She used to look after me, and protect me when my father was – well, not quite himself. But then, when I was about your age, she had to come to Troy to marry a Trojan priest – Calchas, the priest of Apollo...'

'Is he the one who's always having animals sacrificed so he can look at their insides to find out what's going to happen? Why did your sister want to marry him?'

'I don't think she did, really,' said Pandarus. 'And she died a few years later, leaving a little girl called Cressida. So I go to stay with them as often as possible, because I'm the only one Cressida has got left on my side of the family, and she's a nice kid, in spite of having Calchas for a father.'

'Does Calchas think you're a bad influence, too?'

'Probably, but maybe that's just as well. Personally, I wouldn't trust Calchas not to desert and go over to the Greeks' side if he thinks they're likely to win, but he probably won't do that if it means I'm going to be responsible for Cressida – or not until she's grown up. And I wouldn't want to be responsible, anyway. The whole point of being an uncle is that you can be thoroughly irresponsible.'

And that, Troilus knew, was how things worked, with Pandarus. Nobody knew very much about him: not even why, if he was the son of the king of Zeleia, he hadn't brought any chariots or horses or soldiers, or even much armour or equipment apart from a bow and a quiver of arrows. Nobody knew why he didn't rent or buy a house in Troy, as most of the visiting chieftains did. Instead, he lived in the corners of other people's lives, like a stray cat, getting lunch here, dinner there, and a bed for the night somewhere else. But at any rate, he and Troilus were sworn brothers, and nothing was going to change that.

Now I'll need to fast-forward the story about nine years. It's a pity, because I'd like to tell you how Troilus, when he was sixteen, fell heart-over-head in love with Cressida, after her father had deserted Troy; and how Pandarus persuaded Cressida to love Troilus in return, and how they met secretly many times over the next three years. But too many other writers, especially Geoffrey Chaucer, have already told that part of the story much better than I could, so I'll leave it to your imagination, and take up the story again when Troilus was nineteen and Cressida was nearly twenty, to tell what Chaucer and Shakespeare and the others didn't know.

It was nearly morning, and the Dawn was beginning to stroke the sky with pink fingers. The morning light shone through Cressida's bedroom window, and onto the face of the young man asleep beside her. Cressida eased out of bed gently, so as not to disturb him, and began packing her bags. She wouldn't need much, except a few changes of clothes and a book to read; after all, she'd promised she was only going to be away ten days. And when she came back, she wouldn't be in a position to carry much with her, so she'd better not take anything too valuable. But maybe she'd better take a few warm winter cloaks, just in case she couldn't get back for some reason? And it might look suspicious to the Greeks, if she didn't have any luggage. But...

Troilus rolled over into the empty space in the bed, mumbling an argument to himself in his sleep: 'Yes, but if Zeus has always seen me losing Cressida, does he see it because it's going to happen, or is it going to happen because he's seen it? Only Zeus has to make Destiny happen, because... only Destiny happens to Zeus as well...'

Cressida bent over and kissed him on the forehead. 'Wake up and stop worrying,' she said briskly. 'Probably Zeus has always foreseen you not losing me, because he's always foreseen me coming back to you after ten days. I'm just going to visit my dad, you know, not going to the Underworld to steal Hades' guard-dog! Can't you just trust me?'

'Course I trust you,' said Troilus sleepily. 'Sorry, I was just having a bad dream – about werewolves and sphinxes, and Troy burning. Oh Zeus! It isn't today you're going, is it?'

'Yes, that's why you came here last night, remember? You were trying to persuade me to elope with you, and I said I didn't think it was a good idea, and we argued about it and made up, and you stayed the night.' Cressida threw Troilus's clothes onto the bed, and began hurriedly getting dressed herself.

'I still think it'd be better if you did elope with me,' protested Troilus. 'Or if we got married.'

'But if we got married now, when my dad's summoned me to join him in the Greeks' camp, everyone would realise we'd been having an affair, and it'd be embarrassing.'

'I wish we'd got married three years ago,' said Troilus.

'Oh, for Aphrodite's sake!' exclaimed Cressida, now busy brushing her long, silky hair. 'We were too young, and we didn't even know each other then; you'd just caught sight of me once, and had a crush on me. And I didn't even want to have a boyfriend, let alone get married. I told Pandarus I didn't mind being friends with a boy, but I didn't want you to be my boyfriend, and of course he said, "Yes, of course, that's all I meant – you didn't think I was trying to help him seduce you, did I? Would I betray my own niece? It's completely your own decision – only of course if you spurn Troilus, he'll die of misery and then I'll commit suicide and it'll be all your fault – but I don't want to put any pressure on you..."'

'I'm sorry about all that,' said Troilus. 'It's my fault for being too shy to tell you how I felt for myself.'

'Well, it can't be helped now,' said Cressida. 'Anyway, it's nearly morning: time you went home before your mum notices you're not there. Do I look all right?'

'All right? Cressida, you know you're perfect, never mind "all right"!'

'Come on, how could I be perfect? Everyone knows you can't trust a girl whose eyebrows meet in the middle.'

'I like it. It makes you look wise, like an owl.'

'Thank you.' Cressida wondered what Troilus would do if he found out why you shouldn't trust someone with joined eyebrows. As long as they only met once a month, usually on moonless nights, she had just about managed to keep the secret, but he was bound to work it out sooner or later. She wasn't sure whether anyone in Troy knew, apart from Pandarus and her father. A few years ago, Pandarus had told her that a man called Polyphetes was threatening to banish her from Troy and seize her property, so perhaps Polyphetes had known what Cressida was, or perhaps he had just known that she was young, alone and frightened, and the daughter of a deserter.

Or, it occurred to her now, perhaps Polyphetes didn't really exist, and Pandarus had invented him to frighten her. Pandarus loved making every situation as complicated as possible, so that he'd never just say, 'Please can you come to dinner at Deiphobus's house this evening, because Troilus will be there and he really likes you.' Instead, he'd warn Cressida that some man called Polyphetes was plotting to banish her from Troy and seize her property, and that they needed to come to a meeting at Deiphobus's house, with Hector and Paris and Helen, to discuss what to do about Polyphetes. And then, when Cressida was there, he'd tell her that Troilus was lying down in Deiphobus's spare room, because he wasn't feeling very well, and that it would do him a lot of good if Cressida were to go in and say hello to him. And while the two of them were together, Pandarus would be downstairs, telling the other princes how the wicked Polyphetes was threatening his niece and deserved to be hanged, when all the time he didn't even know if there was anyone in Troy called Polyphetes. He was completely unprincipled, devious and manipulative, and probably a psychopath, Cressida decided – but all the same, he was family, and he was also her closest friend apart from Troilus. She was going to miss them both while she was away.

He was knocking on the bedroom door now. 'Are you decent? Can I come in?'

'Sure.' Cressida opened the bedroom door, and Pandarus entered with a tray of bread and cheese and a cup of watered wine. 'I thought you might like – Troilus, what in Zeus's name are you still here for? It's nearly light! You don't want to ruin Cressida's reputation by letting someone see you leaving her house, do you?'

'I'm sorry,' said Troilus contritely. 'I just wanted to say goodbye.'

'Understood. But you'd better get home before your parents wake up and realise you're not there, and start wondering whether you came home at all last night.'

'Goodbye, darling,' said Cressida. 'I expect you'll have to be there with the other princes to see me off, when they hand me over to the Greeks in exchange for the prisoners-of-war, but remember, you don't know me.'

'Yes I do. We met at Deiphobus's house, remember?'

'Okay, we've met once. But it was three years ago, and you've more or less forgotten who I am.' Cressida kissed Troilus one last time, before he could ease the window open and begin climbing down the ivy-encrusted flank of the house. 'I'll be back by full moon, I promise. Only ten days to go.'