'Not necessarily,' Maigret answered quickly. 'God knows what killed Sir Eustace Vechey but there are poisons, Sir Hugh – white arsenic, henbane, foxglove – which can kill as quickly as an arrow to the heart. Remember, Sir Eustace was not a fit man. He was overweight and his heart was growing weak. He may have taken only a few seconds to die.'

Ranulf, leaning against the wall, now unfolded his arms and stepped forward.

'Is it possible,' he asked, 'that Lecroix or anyone else could have changed the wine or water?'

'No,' Maigret explained. 'I saw to that. In Sir Eustace's chamber the windows are mere arrow slits. I examined them carefully. Nothing had been thrown out, and even if it had, how could it have been replaced? There was no more water or a jug of wine in the room.'

'So,' Corbett concluded, 'we have Sir Eustace who dines and wines but only what you eat and drink and even then it is first tasted by others. He goes up to his room with half a cup of wine which was apparently untainted. The same applies to a tray of sweetmeats he kept there and the water with which he washed his hands.' He glanced at Lecroix. 'Your master did wash before he retired?'

The man nodded.

'So, Sir Eustace retired to his bed, locked in a chamber with the key on the inside?' He stared at Branwood who was watching him carefully.

'Yes,' Branwood replied. 'Lecroix opened the door. I heard the key turn.'

'And you, sirs,' Corbett pointed to the soldiers, 'never left your post and no one visited Sir Eustace that night?'

Both men shook their heads.

'On the same evening,' Corbett continued, 'you, Sir Peter, returned to the hall for a cup of wine you had left. Now, if our good physician is to be believed, that too had been poisoned. A mere sip of it turned your bowels to water.' Corbett looked at the friar who had been sitting on a stool, hands on his knees, half-dozing. 'Father, I beg your pardon, Where were you when Sir Eustace's corpse was discovered?'