Jamie swivelled round to face him. 'What's happened, Doctor?'

The Doctor shook his head and crossed his hands over his chest. 'I don't know, Jamie. But I don't like the look of this one bit.'

Cromwell's hard, flushed countenance' suddenly drained as though transfused with milk. He shifted away from Thurloe and sank back into his chair.

'What?' he muttered to himself. Then, again, increasingly louder. 'What? What?'

Blood surged back into his cheeks until he turned almost purple with rage, his bulbous nose wobbling like a great red beacon.

Thurloe bowed his head. 'I'm afraid 'tis true, General.'

Cromwell seemed almost physically afflicted. He pulled himself forward by the arms of the chair but seemed not to have the strength to rise. His eyes stared blankly at the floor for several long moments before fixing themselves on Jamie.

At first he seemed to stare right through the boy, but then he focused more clearly on him. Jamie's hair stood on end.

The general's lip began to curl upward and his breath came in short, stabbing, furious bursts. 'You did not predict this, my Scotch Ca.s.sandra!' he screamed across the room.

The Doctor cleared his throat. 'Predict what, General?' he inquired mildly.

Cromwell seemed about to speak but sank back into his chair, chewing feverishly at his knuckles.

Thurloe turned to the Doctor. 'The King has escaped,' he said simply.

'I beg your pardon?' said the Doctor, genuinely astonished.

Cromwell found his voice and shook his fist at his guests.

'Aye! Escaped! Spirited out of Hurst Castle this very evening as though the walls were made of b.u.t.ter!'

He staggered to his feet and advanced menacingly on the little man. 'You fill my head with talk of flying engines but fail to warn me of this great peril at my very door!'

The Doctor recoiled from the general's wrath and his dreadful breath. 'I explained that the McCrimmon's powers of prediction are not... er, predictable. He sees all possible eventualities. It is up to others to interpret what he sees.'

'Very convenient,' muttered Thurloe, glaring at them with renewed suspicion.

Cromwell swung back to Thurloe and stood with his arms behind his back, his head sunk upon his breast. 'What are we to do, John?'

'I have search parties scouring the city, sir...'

Cromwell held up his hand. 'But it must be kept secret. It must! If Charles escapes abroad there will be another war!'

Thurloe nodded. 'Indeed, General. Only a few commanders know what has occurred. Their men are instructed to seek out an impostor who resembles Charles Stuart and is attempting to stir insurrection among the people.'

Cromwell nodded and allowed himself a little smile.

'You've done well, John. But we cannot waste more time.

Bring Thomas Culpeper to me. I would seek his counsel too.

We must find the King!'

He was about to stomp out of the room when he noticed the Doctor and Jamie again. He growled like a beast at the sight of them.

'And get these two out of my sight. I have had enough of trickery for one day.'

The sound of booted feet approaching made them all look tip and the doors to the room were flung wide. A knot of soldiers marched inside, Thomas Culpeper at their head. The men carried something between them, a figure, its head covered in a cloth sack, kicking and struggling for all it was worth.

'Tom?' said Cromwell. 'What's this?'

Thomas Culpeper saluted Cromwell and then stepped aside.

The figure was flung to the floor where it made renewed efforts to free itself from the ropes that bound it.

'Forgive me, General' said Culpeper, 'but this person was found in the King's quarters at Hurst Castle. She had subst.i.tuted herself for the serving girl employed there and had given drugged wine to the King's guards.'

Cromwell shook his ma.s.sive head. 'What b.l.o.o.d.y treachery is this? She must have had accomplices. What of the other guards?'

'All drugged,' said Culpeper. 'The two she bamboozled say she claimed to be the niece of the old castle retainer, Spufford. But he has flown and must be regarded as the chief suspect.'

Cromwell sighed and slammed his fist into his palm. Then he bent down and ripped the sack from the figure's head.

The Doctor tried to push Jamie back as Polly was revealed but she saw them almost at once, blinking like a newborn lamb.

'Oh, Doctor! Jamie! Thank goodness. I thought '

She glanced quickly round and took in the scene in an instant.

Cromwell's eyes flashed dangerously. 'Well, well. Known to you, eh, Doctor?'

He shook his head disappointedly and then swung his arm over his head wildly. 'Take them all to the Tower!' he screeched hoa.r.s.ely.

Culpeper's men immediately grabbed the Doctor and Jamie. Polly found herself back on her feet and once more in custody.

'You're making a terrible mistake, General,' said the Doctor sadly.

Cromwell didn't reply but turned instead to Thurloe.

'John, you will get the truth out of these people, even if you have to break them in two. Understand me?'

Thurloe nodded. Cromwell swept from the room, his cloak fluttering behind him. 'Captain Culpeper!' he called over his shoulder.

Nathaniel Scrope counted out the last of the coins on to the counter of the merchant's shop and nodded.

'How long's it been, Jabez?' he asked in his cracked voice.

He was standing a dark, low-ceilinged room that bristled with seafaring goods. The walls were thick with coiled rope.

Barrels of salt and tar crowded for s.p.a.ce with ship's biscuits and pewter pots.

The old man across the counter, who looked just as ancient and weathered as Scrope, leaned back on his stool and scratched his sunburnt head.

'Well, now, Nat, that's a good question. You come and did the sc.r.a.pings last when our Betty was having her little 'un.

And that must be all of three year back.' He grinned broadly.

'Aye. Three year come Christmas.'

Scrope chuckled. 'Plenty for me to get my trowels into then, eh, Jabez?'

The other man let out a high-pitched laugh like a whistling kettle and slapped his knee.

'I can't say I'm not glad you've come, Nat. The smell was disturbing my sleep of a night!'

Scrope pulled a strange little spade from his belt and held it up high like a sword. ''Tis the Lord's work I do!' he announced, and he and his friend dissolved into further laughter.

The merchant led the way through the back of the shop and out into the frost-rimed yard. This dingy patch of land was so close to the Thames that it regularly flooded and there was a wide, smooth, frozen pool occupying the bottom half of the yard.

Scrope's attention, however, was fixed on a ramshackle wooden structure which had been erected against the far wall.

Its woodwork was peeled and blistered with age and there were all kinds of unmentionable stains blemishing its surface.

'There she is, Nat,' said Jabez happily. 'As proud a privy as there's to be seen in all London!'

Scrope tapped his hat and scuttled bandily across the yard.

'I'll not be two shakes, Jabez.'

The other man nodded and began to walk back towards his shop. 'I'll prepare us something nice and warm to frighten off this chill.'

Scrope advanced on the toilet with his trowel in one hand and a small leather bucket in the other.

'Now then,' he muttered to himself. 'Where are you?'

Anyone might have thought he was addressing the saltpetre that he came in search of but Scrope seemed more concerned with the back wall of the yard than the stinking structure before him.

He opened the privy door and set his tools down on the hard frozen ground. Inside was a crude wooden shelf with a large hole in it, and beneath that, visible through a muddy hole, was the grey water of the river.

Scrope should have been interested in the deposits that surrounded the hole but he turned and stood by the wall, waiting until a long, low whistle sounded close by.

He placed his filthy fingers in his mouth and returned the signal. Nothing happened for a moment and then, with extraordinary speed, a young boy scrambled over the wall and landed with skill on the hard, frozen ground.

Scrope nodded quickly. 'Good day, Petie. What news?'

The boy was dressed in little more than rags and his cherubic face was smeared with grime. He looked quickly about as though in fear of discovery.

'I've heard tell a woman was seen in Kemp's inn these past couple of nights.'

'A woman like the one I described?' queried Scrope.

The boy nodded. His quick eyes were restless as he continued. 'And she had a man with her but he got coshed on the 'ead. I know someone who saw 'im taken down the docks and put aboard the Teazer Teazer.'

Scrope frowned. 'The Teazer Teazer? She's that Polish captain's ship, ain't she?'

The boy shrugged. Scrope stood in thought for a moment.

'And where was the Teazer Teazer bound?' bound?'

'Amsterdam. But not for long. Due back any time, I hear.'

Scrope nodded. 'And the woman?'

Petie shrugged. 'She was seen with Kemp's daughter but no one has clapped eyes on her in a while.'

Scrope felt inside his purse and slipped the boy a dull metal coin.

'Thank 'ee, Nat,' said the boy with a grin. 'I'll find you again if I hear more.'

Scrope tipped his hat at the boy and watched as he scrambled back over the merchant's wall. He stood in silence for a moment, lost in thought.

The sound of Jabez the merchant whistling tunelessly woke Scrope from his reverie.

Hastily he went back to the privy and, sinking to his knees, began to dig.

The Demeter Demeter seemed to have taken on a life of her own as she ploughed her way majestically through the surging grey waters of the North Sea. seemed to have taken on a life of her own as she ploughed her way majestically through the surging grey waters of the North Sea.

Captain Winter was already on deck as the bleary dawn bled across the horizon. Scanning her ship, she noted with dismay how much damage Stanislaus had inflicted.

Some of her best and most loyal men had lost their lives in the battle with the Demeter Demeter, but now, at least, they had put paid to whatever treachery had been at work. They could get back to London with happy hearts, knowing they had done their best for General Cromwell.

Winter plunged her hand into the pocket of her great green coat and pulled out the bundle of letters she had retrieved from the Pole's cabin. She gazed down at the elegant, florid writing and a small smile formed on her battered face.

Then, swiftly, she put them away again and pulled out her stubby telescope.

She unfolded it and clamped her good eye over the lens, then began to move it back and forth with great deliberation.

Something was niggling at her, a vague uneasiness that she found difficult to ignore.

A big, blurred shape loomed into sight and she jumped in spite of herself, her wooden leg thudding against the deck.

She pulled away the telescope and realised that the shape was Ben emerging from below decks.