‘As I see it, he probably fell through the well head-first and straight into the stream, missing the broken grille, which, by the way, only extends a few inches from the wall. The stream swept him under the grille, but one foot, the right, was trapped between two of the broken fangs. And there he is, held in the current.’

‘How are you sure it’s himself?’

‘By the shoe and the trouser-leg and because—’ Alleyn hesitated.

‘What are you trying to tell us?’

‘It was just possible to see his face.’

‘There’s a terrible thing for you! And so drowned?’

‘That,’ Alleyn said, ‘will no doubt appear in due course.’

‘Are you telling us there’s been—what are you telling us?—a double murder?’

‘It depends upon what you mean by that, Father.’

‘I mean does someone have that sin upon his soul to have killed Violetta and Sebastian Mailer, the both of them?’

‘Or did Mailer kill Violetta and was then himself killed?’

‘Either way, there’s a terrible thing!’ Father Denys repeated. ‘God forgive us all. A fearful, fearful thing.’

‘And I do think we should ring the Vice-Questore.’

‘Bergarmi, is it? Yes, yes, yes. We’ll do so.’

On the return journey, now so very familiar, they passed by the well-head on the middle level. Alleyn stopped and looked at the railings. As in the basilica, they were made of more finished wood than those in the insula. Four stout rails, well polished, about ten inches apart.

‘Have you ever had any trouble in the past? Any accidents?’ Alleyn asked.

Never, they said. Children were not allowed unaccompanied anywhere in the building and people obeyed the notice not to climb the railings.

‘Just a moment, Father.’

Alleyn walked over to the well. ‘Somebody’s ignored the notice,’ he said and pointed to two adjacent marks across the top of the lowest rail. ‘Somebody who likes brown polish on the under-instep of his shoes. Wait a moment, Father, will you?’

He squatted painfully by the rails and used his torch. The smears of brown polish were smudged across with equidistant tracks almost as if somebody had tried to erase them with an india rubber.

‘If you don’t mind,’ he said, ‘I’ve got a fancy to take a shot of this.’ And did so with his particular little camera.

‘Will you look at that, now!’ exclaimed Father Denys.

‘It won’t amount to a row of beans, as likely as not. Shall we go on?’