Before I could stop him, he clapped the mule on its rump, so it skidded out into the arena, dragging Grumio.

'Musa! You idiot. Now he knows we know!'

'Justice must be done,' said Musa calmly. 'I want him to know.'

'Justice won't be done,' I retorted, 'if Grumio escapes!'

On the far side of the arena, the other gate gaped wide. Beyond it a clear vista of the desert was stretching endlessly.

Chapter LXXI

I saw Grumio glance back at us. Unluckily for him, the sturdy figure of Philocrates was holding forth on the mule so there was no chance of bringing the scene to a premature end. Moschion had a lengthy speech about women, which Philocrates enjoyed giving. No wonder. The character was an ignorant bastard; the speech based on himself.

Spinning around, I gripped Davos by his arm. 'I'll need your help. First, Musa! Get around to the end of the amphitheatre, and if it's not too late, slam those gates shut!'

'I'll do that,' said Thalia quietly. 'He's caused enough trouble!' She was a girl for action. She ran for a camel left outside by one of the audience, and within seconds was haring off in a cloud of dust.

'Right, Davos. Go up the back of the arena, and down the steps to the tribunal. Whisper to the commander we've got at least one killer out there, and possibly an accomplice.' I was not forgetting Tranio, currently holed up in a side niche. I had no idea what he might be planning. 'Helena's there. She'll back you up. Tell the man we're going to need some arrests.'

Davos understood. 'Someone will have to fetch that bastard off-stage:' Without hesitation, he threw his stage mask at a bystander, stripped off his white ghost's costume, and dropped it over my head. Wearing only a loincloth, he ran off towards the commander. I was given the mask.

I found myself shrouded in long folds of material that flapped strangely on my arms – and in darkness. The ghost was the only character we were playing in a mask. We rarely used them. I knew why the minute I had this one rammed over my face. Suddenly excluded from half of the world, I tried to learn how to look through the hollow eyes, while scarcely able to breathe.

A bothersome presence was grabbing my elbow.

'He's guilty then?' It was Congrio. 'That Grumio?'

'Get out of my way, Congrio. I've got to confront the clown.'

'Oh I'll do that!' he exclaimed. The certainty in his tone carried a familiar echo of Helena's brisk style. He was her pupil, one she had clearly led astray. 'Helena and I have thought up a plan!'

I had no time to stop him. I was still trying to master my costume. Adopting a curious sprint (his idea of great acting, apparently), Congrio raced into the arena ahead of me. Even then I still expected to hear the one line I had written for him: 'Madam! The young lady has just given birth to twins!'

Only he did not say the line.

He was not playing the part I had written him, but the traditional Running Slave: 'Gods above, here's a pickle -' He ran so fast he caught up the travellers on their mule. 'I'm wearing myself out. Moschion turned out of doors, his mother in tears, the roast on fire and the bridegroom furious, and now this girl – hold on, I'll tell you all about the girl when I get round to it. Here's a pair of travellers! I'll stop for a chat with them.'

Then, as my heart sank further than I had ever thought it could, Congrio began to tell a joke.

Chapter LXXII

Congrio had climbed up on a model of a rock for a better view. 'Hello down there! You look glum. Would you like cheering up? Here's one I bet you haven't heard.' Philocrates, still on the mule, looked furious. He liked to know where he was with a script, and hated minions anyway. Congrio was unstoppable.

'A Roman tourist comes to a village and sees a farmer with a beautiful sister.'

I noticed that Grumio, who had been about to tug the mule's reins, abruptly stopped, as if he recognised the joke. Congrio was revelling in his new power to hold an audience.

' "Ho there, peasant! How much for a night with your sister?"

' "Fifty drachmas."

'"That's ridiculous! Tell you what, you let me spend a night with the girl and I'll show you something that will amaze you. I bet I can make your animals talk: If not, I'll pay you the fifty drachmas."

'Well the farmer thinks, "This man is crazy. I'll string him along and agree to it."

'What he doesn't know is that the Roman has been trained as a ventriloquist.'

'The Roman reckons at least he can have a bit of fun here. "Let me talk to your horse, peasant. Hello, horse. Tell me, how does your master treat you then?" '

' "Pretty well," answers the horse, "though his hands are rather cold when he strokes my flanks:" '

As Congrio rambled on, I could just make out through the mask that Philocrates looked stunned, while Grumio was seething furiously.

' "That's wonderful," agrees the farmer, though he isn't convinced entirely. "I could have sworn I actually heard my horse speak. Show me again." '

'The Roman chuckles quietly to himself. "Let's try your nice sheep then. Hello, sheep! How's your master?" '

' "Not too bad," says the sheep, "though I do find his hands rather cold on the udder when he milks me:" '

Philocrates had assumed a fixed grin, wondering when this unplanned torture was going to end. Grumio still stood like bedrock, listening as if he could not believe it. Congrio had never been so happy in his life.

' "You're convincing me," ' says the farmer.

'The Roman is really enjoying himself now. "I knew I would. I'll do one more, then your sister's mine for the evening. Hello, camel. You're a lovely-looking creature. Tell me – " '

'Before he can go any further, the farmer jumps up furiously. "Don't listen to him! The camel's a liar!" he shrieks.'

Someone else was jumping up.

With a cry of rage, Grumio flung himself at Congrio. 'Who gave it to you?' He meant his scroll of jokes. Helena must have lent it to Congrio.

'It's mine!' The bill-poster was taunting Grumio. He sprang down from the rock and leapt about the stage, just out of reach. 'I've got it and I'm keeping it!'

I had to act fast. Still wearing the ghost's costume, I entered the ring. In the vain hope of making the audience believe my appearance was intentional, I waved my arms above my head and ran with a weird loping gait, pretending to be Moschion's paternal phantom.

Grumio knew the game was up. He abandoned Congrio. Spinning around, he suddenly grabbed Philocrates by one smart boot, gave a wrench of his leg and pulled him off the mule. Not expecting the assault, Philocrates crashed to the ground horribly.

The crows roared with appreciation. It was not funny. Philocrates had fallen on his face. His handsome visage would be ruined. If only his nose was broken, he would be fortunate. Congrio stopped cavorting and ran to him, then pulled him towards the side niche, from which Tranio now emerged, also looking shocked. Together they carried the unconscious actor from the ring. The crowd were thrilled. The fewer cast members left still upright, the more delighted they would be.

Ignoring the rescue of Philocrates, Grumio was trying to mount the mule. I was still stumbling over the long hem of my costume, half blind in the mask. I struggled on, hearing the crowd's bursts of laughter, not only at my antics. Grumio had not reckoned with the mule. As he swung one leg to mount, the animal skittered sideways. The more he tried to reach the saddle, the more it veered away from him.

Amusement soared. It looked like a deliberate trick. Even I slowed up to watch. Hopping in frustration, Grumio followed the mule until they actually came face to face. Grumio turned to approach the saddle again, then the mule twisted, shoved him in the back with its long nose, and knocked him flat. Whinnying with delight at this feat, the mule then galloped from the scene.