‘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.