They were halfway up Cheapside when a small voice called out: 'Sir John! Sir John!'

They stopped. A little boy ran up, face dirty, clothes dishevelled, his breath coming in short gasps so he could hardly speak. Sir John stood back and Athelstan smiled. Cranston always seemed to have a fear of small boys. Perhaps a memory from childhood when a fat Cranston must have been mercilessly teased by others. Athelstan knelt before the child, taking his thin, bony hand.

'What is it, lad?' he asked gently. 'What do you wish?'

'I bring a message from the Sheriff,' the boy gasped. 'Master Vechey…' The child closed his eyes to remember. 'Master Vechey has been found hanged under London Bridge. The Sheriff says it's by his own hand. The body has been cut down and lies in the gatehouse there. The Sheriff sends his com – '

'Compliments,' Athelstan interrupted.

'Yes.' The boy opened his eyes. 'Compliments, and wishes Sir John to go there immediately and examine the corpse.'

Cranston, standing behind Athelstan, whistled softly.

'So, we were right, Brother,' he said, tossing a coin to the boy who scampered away. 'There is evil afoot. One murder can be explained, one suicide can be accounted for, but another suicide?' His fat face beamed. 'Ah, no, Sir Richard may be pompous, Lady Isabella frosty, Dame Ermengilde may strike her cane on the floor in temper, but Vechey's death cannot be dismissed. There is evil here, and you and I, Athelstan, will stay like good dogs following the trail until we sight our quarry. Come! The living may not want to talk to us but the dead await!'

And, without even a reference to refreshment, Cranston waddled off down Cheapside with Athelstan striding behind him. They pushed their way through the morning crowd: monks, friars, hucksters and pedlars, ignoring the shouts and screams of the city as they turned into Fish Hill Street which led down on to London Bridge. They stopped at the Three Tuns tavern to ensure their horses had been well stabled. Cranston paid the bill. Philomel, happy to see his master again, nuzzled and nudged him. The road down to the bridge was packed so they decided to leave their horses rather than ride.

At the entrance, just near the gatehouse door, Cranston stopped and knocked hard at an iron-studded door. At first there was no reply so, picking up a loose brick, Cranston hammered again. At last the door was opened. A small, hairy-faced little creature appeared, a veritable mannikin who glared up at Sir John.

'What do you want?' he roared. 'Bugger off! The gatehouse is closed on the king's orders until the arrival of the coroner.'

'I am the coroner!' Cranston bellowed back. 'And who, sir, are you?'

'Robert Burdon,' the mannikin retorted. He rearranged his cloak and stuck his thumb into the broad leather belt at his waist like a wrestler waiting for his opponent to attack. Sir John ignored him and pushed forward into the dank entrance of the chamber.

'We have come to view Master Vechey's body.'

The mannikin ran in front of Cranston, jumping up and down.

'My name is Robert Burden!' he shrieked. 'I am constable of this gate tower. I hold my office direct from the king!'

'I don't give a fig,' Cranston replied, 'if you hold it direct from the Holy Father! Where's Vechey's corpse?'

He looked into the small chamber near the stairs where the mannikin probably ate, lived and slept. A small baby crawled out on its hands and knees, its face covered in grime. The mannikin picked it up, shoved it back in the chamber and slammed the door behind him.

'The corpse is upstairs,' he said pompously. 'What do you expect? I can't keep it down here with my wife and children. The cadaver's ripe.' He indicated with his thumb. 'It's on the roof. Up you come!' And, nimble as a monkey, he bounded up the stairs ahead of Cranston and Athelstan. He pushed open the door at the top and led them out on to the roof, a broad expanse bounded by a high crenellated wall. The wind from the river whipped their faces. Cranston and Athelstan covered their face and nose at the terrible stench which blew across.

'God's teeth!' Cranston cried as he looked around. Vechey's corpse lay in the centre of the tower near a rickety hut, formerly used by guards on sentry duty. The body lay sprawled, its face covered by a dirty rag. Athelstan thought the odour came from that but, looking around, he saw the rotting heads which had been placed on spikes in the gaps of the crenellated wall.

'Traitors' heads!' Cranston muttered. 'Of course, they spike them here!'

Athelstan looked closely, trying not to gag. Like all Londoners he knew that once the bodies of traitors had been cut and quartered, their heads were sent to adorn London Bridge. He looked closer. Thick, black pools around the spikes showed some of the heads were fresh, though all were rotting, crumbling under the rain and wind which whipped up their oddly silken hair. Large ravens which had been busy, plucking out juicy morsels with their yellow beaks, rose in angry circles above them.

'Their hair,' Athelstan whispered. 'Look, it's combed!'

'I do that!' the mannikin cried. 'I always look after my heads! Every morning I come up and comb them, keep them soft, pleasant-looking. That is,' he added morosely, 'until the ravens start pecking them, though they usually leave that bit for the last. Oh, yes, I comb their hair and, when I am finished, I sing to them. I bring my viol up. Lullabyes are best.' He looked up at Athelstan, his face beaming with pride. 'Never lonely up here,' he said. 'The things these heads must know!'

'God's teeth,' muttered Cranston. 'I need refreshment! But never mind that. This morning I swore a mighty oath not to touch the juice of the grape or the crushed sweetness of the hop. But first let's see Vechey's corpse.'

The mannikin skipped over to show them the unexpected addition to his ghastly collection. He whipped off the rag which the wind caught and blew against one of the spiked heads.

'You examine it, Brother,' whispered Cranston. 'I feel sick. Last night's wine.'

Athelstan crouched down. Vechey was dressed in the same clothes as yesterday. The soft face was now puffier, its colour a dirty white. His eyes were half open, mouth slack, lips apart, displaying rows of blackened teeth. Vechey seemed to be grinning up at him, taunting him with the mystery of his death. Athelstan turned his head slightly to one side. He caught his knee on his robe and slipped. He felt queasy as his hand touched the cadaver's bloated stomach and noted that the dead man's legs were soaking wet. He inspected the gash round Vechey's neck, which was very similar to that of Brampton; black-red like some ghastly necklace and the dark, swollen bruise behind the left ear. He held his breath and sniffed at the dead man's lips. Nothing but the putrid rottenness of the grave. Then he examined the corpse's hands. No scars, the nails neat and clean, shorter than Brampton's. There was no trace of a strand of rope caught there. Athelstan looked at the mannikin.

'Where's the noose?'

'I tossed it away,' the fellow replied triumphantly. 'I see'd him there, I cuts him down, I loosened the noose and it falls in the water.' His face grew solemn, his eyes anxious. 'Why, shouldn't I have done that?'

'You did well, Robert,' Athelstan replied quietly. 'Very well. You found the body?'

'Well, no, my children did. They were playing where they shouldn't, on the starlings under the bridge. You know the wooden barriers around the arches?' He shook his head. 'So many of them. Nine, I have,' he declared. 'Should be ten but the eldest got drunk and fell in the river!'

Cranston stared in utter disbelief at the mannikin's potency.

'So you cut him down?' he asked. 'How did you know it was Vechey?'

'I found coins in his pocket and a piece of parchment. It had his name on it. That and someone else's. Thomas…' he closed his eyes.