"Rufus, thank the gods! It's awful in there - like a nightmare. All Chloe's people are terrified, saying she's poisoned the master and she'll be putting the blame on one of them. And as for Chloe herself - first she was as sick as a dog, and you can imagine the drama . . ."

"Sick, you say? Is it serious?"

"Not really. I suppose the wine's made her ill, but at least she didn't drink enough to kill her, like poor Master Marcus. The wine was poisoned, presumably?"

"It was the pearls and wine that made a poisonous mixture," I said. "That's what Sabinus thinks, and so do I. The point is, did Chloe know it would happen like that? I need to talk to her. Is she in a state to see me?"

Amanda shrugged. "I expect so, if you insist loudly enough. Use the Lady Cornelia's name, I should; that'll scare them all. And make it quick. I've got some medicine here to make her sleep, something the old lady's doctor has made up for her. She's hysterical, howling the place down like a child that's lost its favourite doll." She sniffed scornfully. "She keeps saying 'I didn't mean to kill him', over and over again. He's dead just the same, poor boy."

"I don't think she did mean to," I answered. "After all, she drank the wine herself before she gave it to him. If she'd known it was poisonous . . ."

"Yes, that's true," Amanda conceded. "And originally she meant to drink it all herself."

"You knew she was going to make that silly scene? You knew beforehand?"

"Oh, yes, all the servants did. She'd been planning it for ages, that's why she made him buy the pearls. She went on and on about it, going over what she'd say, how it was so romantic . . . we were all sworn to secrecy on pain of a serious flogging, so I couldn't tell you. But she was determined to drink it all herself. She never mentioned making Master Marcus drink any. That must have been a sudden whim, not in the original plan."

"Unless she was being really cunning, and planning to poison Marcus but telling you all she would be drinking the mixture . . . no, that's too far-fetched. Why would she kill a man who adored her, when she was all set to marry him? Still, it's a funny way to treat a fabulously expensive present from your lover. Didn't she like the necklace?"

"Oh, she loved it. The way she stroked it and played with it and kept it safe . . ."

"Kept it safe?" I repeated. "I wondered about that. Granted she didn't poison the drink on purpose, could the pearls have had some kind of dirt on them, picked up from the shop where they were bought, or from someone handling them?"

Amanda shook her head. "None of us were allowed to touch them. Cousin Phoebe offered to polish them once or twice, but Madam said she was too rough, and after that nobody but Chloe herself went near them."

The door into Chloe's suite opened abruptly, and Phoebe stood there. She'd been crying, which made her lovely face look ugly and hard.

"Amanda! Don't stand gossiping, girl. Hurry up with that sleeping-draught! My poor cousin's beside herself. She must have some medicine to calm her down."

"Coming, my lady," Amanda stepped through the door; I followed, and Phoebe was too preoccupied to stop me.

I don't often go into ladies' private apartments and, whenever I do, I feel like a bull in a glassware shop, several sizes too big and clumsy for the delicate furniture and feminine frippery all around me. I took refuge in being brusque and to the point, and said, "Where's the Lady Chloe?"

"In her bedroom," Phoebe answered, noticing me now. "And who might you be, barging in here without a by-your-leave?"

"Lady Cornelia sent me to ask after your cousin," I said. The lie worked. "Oh, I see. It's not a good time, but . . . how is her ladyship?"

"She's recovered from her fainting fit, but she's in extreme distress over this whole tragedy. She's ordered me to enquire after Lady Chloe, and get to the truth of what happened."

"I'd have thought it was obvious, even to a stupid hulk like you," she retorted, tossing back her dark hair and fixing me with an angry stare. "My poor cousin wanted to make a romantic gesture, and it went tragically wrong. The pearls somehow poisoned the wine. The story of Queen Cleopatra and her banquet is so well known, nobody questioned that it's true. Obviously it can't be."

"That's certainly how it seems," I agreed, softening my tone a bit. "But I still would like to talk to your cousin. Please. Won't you ask her if she'll see me, just for a little while?"

"It's all right, Phoebe." Chloe herself appeared from one of the inner rooms and came towards me. "I'll see him if I must. Ah - you're one of Marcus' brother's people, aren't you?"

"I'm his assistant, my lady. Rufus, at your service." I had trouble not staring rudely at her; she was changed out of all recognition from the glamorous beauty of the banquet. Her skin was blotchy, her eyes were swollen, and some strands of golden hair had come loose and hung down untidily. She had torn her lovely dress in the ritual gesture of mourning, and there were stains down the front of it where she'd been sick.

"Lady Cornelia asked me to come and see you," I said. "I'm sorry to disturb you, but . . . we're all so deeply sorry about this tragic accident."

"Accident?" She almost shrieked the word. "Yes, I suppose you can call it that. I killed him. I know I did. But I didn't mean to. I didn't mean to. Gods, I've been so stupid, so incredibly stupid, and now I've killed him! I didn't want the marriage, or him, but - may the gods witness, I didn't want him dead!" She flopped down onto a couch and started sobbing.

I sat down beside her. Normally I would wait to be asked, but I was towering over her like a granite obelisk, and I thought it might intimidate her.

"You didn't want to marry Marcus?" I asked gently.

"Of course I didn't!" Cleopatra was back in control for a few heartbeats, then Chloe began crying again. "There was a man in Alexandria, I loved him, and he loved me. But my father insisted it had to be Marcus, and he loved me too, the poor sweet idiot. Only I couldn't love him. Why else d'you suppose I gave him such a hard time?"

"You were hoping he'd fall out of love? But the marriage would have gone ahead, surely. Love and marriage don't have to go together." Nobody knows that better than we Romans.

"I thought - I don't know what I thought. I was trying to make him hate me, that would have been a start. Only he went on loving me! And I didn't want him dead. You must believe that!"

"So you didn't realize," I said softly, "that dissolving pearls in wine would make the wine poisonous?"

She shook her head sadly. "I thought that anything Cleopatra did, I could do too."

I got away eventually, and went with a heavy heart to tell Sabinus. I found him in the garden, gazing moodily into the pool.

He nodded as I came up, then turned back to stare into the water, which was full of starry reflections. "I can't do any more till daylight," he said. "But dawn won't be long. Rufus, this is all such a mess, such a tragic waste." He turned and looked at me. "Well, tell me the worst. What have you found out?"

He wasn't surprised by what I told him, except for the bit about Chloe not wanting to marry Marcus. He seemed even a little relieved that she was a thoughtless irresponsible child, but at least not a calculating murderess. "After the funeral, we'll ship her back to Egypt," he said. "I expect she can make a decent marriage there."

And your dear mama will have to find some other way of refilling the family coffers, I thought, as I left him and headed for my sleeping-quarters. Amanda would still be with Chloe; I'd be alone for what remained of the night. As I walked down the badly lighted narrow corridor that led to the rooms where we freedmen slept, a dark figure moved in the shadows. My hand went to my knife, but it was only the Egyptian boy, still clutching his monkey. He stood in front of me, blocking my way.

"Please, my lord," he said. "My monkey sick."

"Sick? Well then, fetch an animal doctor, and get out of my way." I made to brush him aside, but he stood his ground.

"My lord, please. Something bad is." His dark thin face was serious, and his eyes were big and intense. Whatever he was trying to tell me, it was important. I didn't want to be bothered with him or his monkey, but I could remember the days when I was a slave-boy and nobody listened.

"Tell me then," I said. "Only if you're not quick, I'll be asleep on my feet."

"Monkey sick from touch pearl out of wine-cup. He only just lick paw, so he not die. But wine was -" he searched for a word "- was dirty."

"Dirty?" I couldn't make sense of it. "Look, if you've got something to say, boy, speak Greek if it's easier, but for the gods' sake get on with it."

He nodded. "Good. For Egyptian boy, Greek is better. I want to make you understand. Poor monkey sick because the wine was poison."

"Actually we worked that out," I snapped. "The pearls poisoned it."

"No, pearls not poison."

Curse the boy, his Greek seemed no better than his Latin. "Pearls," I said loudly, in slow, simple Greek, "dissolve in wine. The wine - eats them up. You understand? When the pearls have been in the wine, the wine is changed into poison."

"No, no!" he gestured excitedly, making the monkey wriggle. "I seen it done before. Pearls and wine. The Cleopatra game."

"The what?"

He grinned suddenly. "I worked for master who did magic tricks. Very quick hands. Turn gentleman's cup into dove, or take snake out from under lady's cloak. You know?"

"Yes, I know the kind of thing." In Egypt, magic-show entertainers are plentiful, and often very good.

"He use to put pearl in cup of wine, pretend to make it dissolve in the wine. But it never."

I looked at him sharply. "Go on."

"Pearl not dissolve in good wine. In sour wine, in vinegar, yes, it get slowly eat up." He screwed up his mouth to indicate a bad taste. "Not in good stuff. Master use to leave pearl in wine little time, then he drink all wine, tell the people he drink pearl too. Cup empty - pearl hid in hand. Then he fill another cup, make pearl come out of that. Pearl not hurt, a little dull maybe, but soon polish. He call it the Cleopatra Game. And it never make him sick to drink. Once only it make him sleepy."

"Why?"

"I play joke on him. I rub sleeping stuff on outside of pearl. It wash off into wine, and he drink it, and he sleep. When he waked up, he beat me."

"Gods alive!" My mind was racing. Now I knew how Marcus had been killed - but I still didn't know the killer. Or rather, I didn't know which one of two . . .

"My lord?" The boy interrupted my thoughts. "Did I explain it clear?"

"Yes, lad. And thank you - you were right to tell me. Off you go now. I need to think." I threw him a silver piece, and he scampered off, grinning. I stood alone in the passageway, staring at nothing, just thinking hard.

Either Chloe or Phoebe had poisoned the pearls. Both had had the chance; even though Phoebe wasn't supposed to touch the necklace, I felt sure she could have found a way. Chloe was the more likely though. She hadn't wanted to marry Marcus; by using the pearls and wine she could make his death look like a tragic accident. And she'd been clever, talking about how she intended to drink all the wine, giving no hint that she planned to offer it to Marcus.

But then Phoebe also had a reason to kill - not Marcus, but her cousin, who was marrying the man she herself loved. Phoebe had heard Chloe boasting that she would drink the pearls, and knew that she'd forbidden everyone else to touch them; so if Chloe died, here again it would appear to be a terrible accident, or if the poison was discovered, we would conclude that Chloe had chosen suicide to escape her wedding.

Standing there in the near-dark, I worked out a way to discover which of them had perpetrated this cunning, premeditated killing. All it needed was a little play-acting, and two small items which I went and collected from my sleeping-room nearby: a large linen cloth, and an empty leather money-bag.

Then I ran back through the house to Chloe's suite. I hammered on the door, but nobody answered my knock, so I walked in.

The outer room looked dim and deserted, with only one small lamp burning. Presumably the ladies, and their maids, were in their bed-chambers.

"Lady Chloe! Lady Phoebe!" I called loudly. "It's Rufus, and I'm sorry to disturb you, but I need to talk with you both now. Come out, please. I'm afraid this is urgent."

There was silence. I looked at the two bedchamber doors. I'd have to go in and rouse the women, but maybe I should fetch a couple of our household maids to help me.

"Rufus?" a voice said. "So you've come back." And then I saw Phoebe, sitting on a reading-couch in a dark alcove. She looked flushed; I wondered how much more she'd drunk. "What do you want?"

"Lady Phoebe." I came and stood over her, and this time I didn't worry about towering above her, because a granite obelisk was what I felt like. "Will you please fetch your cousin? I need to talk to both of you urgently."

"You can't talk to Chloe," she snapped, not troubling to hide her hostility. "She's in bed, and sound asleep by now, I hope. She's taken a strong sleeping-draught, and she's not to be disturbed. You can talk to me, if you must."

"Very well then. I've discovered," I said carefully, "that Marcus' death wasn't an accident. The wine was deliberately poisoned."

"Deliberately? But - how dreadful! It wasn't just the mixing of the pearls and the wine?"

"No. Pearls and good wine don't form a poison. Where are the pearls, please? I must lock them away. They're extremely dangerous."

"They're safe enough now." She gestured towards a small table beside her couch. It had a silver cup of red wine on it, and a covered silver fruit dish. She lifted off the lid, and revealed the pearls in a loose pile, gleaming richly even in this dim light. "So pure, aren't they? So perfect . . ." She picked up a handful, and let them run slowly through her fingers.

"Put them down!" I exclaimed. "I tell you, they're dangerous. They've been poisoned. Even just touching them could be deadly." I produced my cloth, and used it to scoop the pearls into my leather bag, making a great show of not letting the jewels touch my fingers.

"What nonsense!" she retorted. "Chloe wore the necklace all through the banquet, right against her skin . . ."

"The pearls were dry then. It's wetting them that brings the poison out. The effect of liquid . . ."

She was following my movements intently as I gathered the last of the pearls. I've long ago perfected the knack of watching someone without appearing to, so I didn't miss her quick glance down at her hands. And she had said the pearls were safe enough now. I felt the tingle of excitement a hunter knows when he has laid his bait, and watches the quarry approaching his trap.

"Marcus was murdered," I went on, pulling the bag's drawstring tight. "Poison was smeared onto your cousin's necklace, and it was a special kind that only becomes lethal when it touches liquid. If you drink the liquid it kills you - as it killed poor Marcus. And if you touch it, it kills you too, only more slowly."

"How?"

"Say you washed the pearls. The water would be poisonous, and it would eat into your skin - not immediately, but in an hour, maybe two, you'd feel it start to burn and blister. And then . . ." I let it hang.

She had gone white. "And then?"

"The poison would work through the blisters, and seep into your body. You'd be dead inside half a day."

"But I've dried my hands!" she cried. She spread her hands out and stared at them; they were quite unharmed - of course they were. I was making this up as I went along. But my bait had trapped her, and when she looked up at me again, I saw that she knew it.

"You washed the pearls, Lady Phoebe," I said. "To clean off the poison you had smeared on them."

She said nothing.

"Did you hate your cousin so much?"

She sat unmoving; I thought she wasn't going to answer. Then she said, so quietly it was almost a whisper, "I loved Marcus."

I waited.

"I loved him from the first time I saw him. He didn't want me, I knew that, but I couldn't not love him. And I hated Chloe for the way she treated him. I'd have given him love, kindness, respect - I'd never have humiliated him the way she did."

"Yet you killed him."

"But I didn't mean to!" she exclaimed. "She was the one I wanted dead! I was trying to protect him from her. I knew if she was dead he still might not love me, but at least he could live his life without her trampling all over him!"

"Wasn't there any other way out? Your cousin didn't want to marry Marcus, after all."

"Both families insisted on it. Marcus and Chloe - a union of rank with riches. The perfect Roman marriage." Her tone was like a bitter wind.

"But deciding to kill her . . ."

"Ah, no! She would have killed herself, by the choice she made. I worked it out carefully. If she died, she'd die by her own hand, and she'd deserve it."

"I don't understand."

"I tried to talk her out of her plan to drink the pearls, but of course that only made her more determined. I suppose I should have known it would. But it was cruel - and wasteful.

Such lovely pearls! If Marcus had given me pearls like that . . . So I thought, let her wear them, but not destroy them. I contracted a man who - never mind; it isn't hard to find such people. He supplied a poison that wouldn't harm her skin, but would kill her if she swallowed it. I rubbed it on the necklace this afternoon, while she was taking her bath. And then it was her decision. If she wore the pearls, she'd be safe. If she drank them, she would die."

Suddenly she began to cry. Not the loud, dramatic weeping I'd seen earlier; this was agonising, gut-wrenching sorrow. "How was I to know she'd give the wine to Marcus? She said she would drink it all . . . but she had to go one better, and humiliate him yet again! And poor Marcus . . . !"

She wiped her eyes, getting herself under control. "I sat at that banquet, and I vowed in my heart, I'll get you yet, you vicious little snake. And now I have."