'How else did it happen?' Sir Richard asked stiffly.

'Well,' Cranston said, 'is it possible that Brampton took the wine cup as a peace offering to his master?' He ignored the sneer on Vechey's face. 'Placed it on the table and then left?'

'And?' Lady Isabella asked.

'Someone else went up those stairs during the banquet and put poison into the cup. Or,' Cranston rubbed his fat hands together, now warming to his subject, 'how do we know that Sir Thomas did not have a visitor after he retired? Someone who went up the stairs and along the gallery, slipped into Sir Thomas's room, perhaps engaging him in conversation and, while doing so, secretly poured the poison into the cup.' He held up a hand to still the murmur. 'I am just theorising, as the theologians say, speculating on the nature of things.'

Then, Sir, you are a fool!'

Cranston, Athelstan and the whole company turned round in astonishment and looked down the hall. In the doorway stood an old lady dressed completely in black like a nun. Her head was covered by a thick, lawn veil arranged in the old-fashioned wimple which framed her sour lemon face in its black lace. She walked forward, her silver-topped stick beating loudly on the hall floor.

'You are a fool!'

Cranston rose.

'Perhaps I am, Madam, but who are you?'

Sir Richard darted forward.

'Lady Ermengilde, may I present Sir John Cranston, coroner of the city.'

The old lady glared at the coroner with eyes like two dark pools.

'I have heard of you, Cranston, your drinking and your lechery! What are you doing in my son's house?'

'Sir John is here at the request of Chief Justice Fortescue.' Sir Richard's voice was soft, almost pleading.

'Another rogue!' the lady snapped.

'I asked, Madam, to whom do I have the pleasure of speaking?' Sir John repeated.

'My name is Lady Ermengilde Springall. I am the mother of Sir Richard,' she stroked Springall's arm. 'My other son now lies dead upstairs and I come down to hear you chatter on about nonsense. Brampton may have been a good steward. He was also a varlet, a commoner! He had ideas above his station. Thomas rebuked him, and like many of his kind Brampton could not take it. His heart was filled with malice. Satan whispered in his ear, and he carried out his dreadful deed.' The old woman crashed her stick to the floor and held it between her two hands, resting on it. 'At least Brampton did us all the courtesy of hanging himself and so sparing the public expense and the work of the hangman at the Elms!'

Athelstan watched Cranston. The coroner was now in one of his most dangerous moods. He smiled but only round the lips. His eyes were hard and fixed, watching the old lady as a swordsman might an opponent waiting for the next parry.

'Lady Ermengilde, you seem well appraised of what happened. I crave your indulgence. Can you explain more?'

'My chamber is close to that of my son,' she snapped. 'The staircase beyond,' she indicated with a nod of her head, 'leads up to two galleries, one running to the right. At the end was Sir Thomas's chamber and, next to his, mine.'

'Any other?'

Lady Ermengilde's eyes slid towards her daughter-in-law.

'That of the Lady Isabella. There is a gallery to the left, identical to the one I've described except for one thing.' She raised one bony finger. 'My chamber, as well as those of Sir Thomas and Lady Isabella, stands on the Nightingale Gallery.'

'The Nightingale Gallery?' Athelstan asked. 'What is that?'

Dame Ermengilde smiled and walked nearer, her face looking more than ever like a sour apple. Athelstan noticed she was not dressed in black but in the dark brown habit of a nun, though her scorn for the luxuries of this world must have been shallow for the rings on her fingers held jewels the size of birds' eggs. A worldly lady, Athelstan thought, for all her prim face, sour lips and arrogant eyes.

'It's well known,' she continued, her voice tinged with patronising arrogance. 'This house was built on a square, and on the opposite corner of the square are stairs to the second storey.' She waved her hand to the far doorway which stood slightly ajar. Through it Athelstan could glimpse steep stairs. 'They will take you up to Sir Thomas's chamber,' she added. 'At the top are two corridors. The gallery to the right is the Nightingale Gallery because it "sings" when anyone walks through it.' She must have seen the disbelief in Cranston's bleary eyes. 'This house is very old,' she continued, looking up at the great blackened beams. 'It was built in the reign of King John.' She smirked. 'A time very like our own. A strong ruler was needed. Anyway, one of John's mercenary captains used this house as a base from which to control London. He trusted no one, not even his own men.' Her eyes drifted to Lady Isabella who was standing behind Athelstan. 'Anyway, he had the floor of that gallery taken up and replaced with special boards of yew. No one can approach any of the three chambers on that gallery without making it creak, or "sing". Hence its name.'

'And the importance of this?' Cranston asked.

'The importance, my dear coroner,' she purred in reply, 'is that I was in my chamber all evening. I am old and banquets bore me. Oh, I heard the talk and the laughter from the hall below. It disturbed my sleep. Fortunately I need very little.' She glared at Cranston. 'You will find out for yourself, Sir John, age makes you sleep lightly.'

'Just in case Death taps you on the shoulder!' he answered crossly.

'Quite,' she jibed back. 'But Death has a tendency, as you well know, Sir John, to take the heaviest first!'

'My Lady,' Athelstan intervened, 'the events of yesterday… You heard no one go up to Sir Thomas's chamber?'

'Before the banquet people were scurrying backwards and forwards,' she retorted. 'During the meal I heard the Nightingale sing once, I was surprised. I opened the door and saw Brampton, carrying a wine cup in his hand. I heard him open the door to my son's chamber and then go back downstairs again. I heard no other noise before Sir Thomas's footsteps when he came up to his chamber. Sir Richard followed him and bade him goodnight, then Lady Isabella's maid made her inquiry. After that the house was silent till this morning. Father Crispin came up, I heard him knock on the door, then he went for Sir Richard and brought him back.'

Cranston nodded. 'I thank you, Lady Ermengilde. You have solved one piece of the puzzle, Brampton did take the cup up. Now,' he looked at Sir Richard, 'disturbing and painful though it may be, I must insist that I view the bodies of both men.' He bowed to Lady Isabella. 'Your husband first, My Lady. You have no objection?'

Sir Richard shook his head and led them out across the hall and up the broad sweeping staircase. As Cranston passed Lady Ermengilde, he belched rather noisily.

At the top of the stairs the passageway, or gallery, to the left was unremarkable. The walls were white-washed and coated with fresh lime, the woodwork painted black. There were canvas paintings nailed there in between the three chambers which were now covered in black gauze veils; the doors of each chamber were huge, heavy set, and reinforced with iron strips. The gallery running to their right, however, was different. The doors and walls were similar but the floor was not made of broad planks but thin bands of light- coloured wood. As soon as Sir Richard stepped on them Athelstan realised the gallery was aptly named. Each footstep, wherever they stood, caused a deep, slightly melodious twang, similar to the noise of a dozen bowstrings being pulled back simultaneously. Immediately to their left was Lady Isabella's room, the central chamber was Lady Ermengilde's, and the last Sir Thomas's, now in utter disarray. The floor outside was gouged. The door, smashed off its leather hinges, stood crookedly against the lintel. Sir Richard dismissed the servant on guard and, with the help of Buckingham, pushed it gently to one side.