'What on earth do you mean, man?' asked Ravengar, whose voice was always
gruff.

'I refer to Polycarp's visit yesterday.'

'I know nothing of it,' said Ravengar slowly, looking across the
wilderness of roofs.

'Then why are you here, Louis? Is your revenge at last matured?'

Ravengar controlled himself, and glanced round as if for unseen aid in a
forlorn enterprise.

'Owen,' he said, moved, 'I'm here because I need your help. I won't say
anything about the past. I know you were always good-natured. And you've
worn better than I have. I need your help in a matter of supreme
importance to me. I became aware last night that you and your men were
interested in the proceedings at Tudor's flat. I ran here, meaning to
see you. There was no one in the big circular room downstairs, and no
one at the entrance. Then I saw your servant coming, and I retreated
through the door. I wished my presence to be known only to you. The door
was locked on me. I knocked in vain. Then I stumbled up the stairs, and
found myself out here. I wanted to calm myself, and here I remained. I
knew your habit of coming up here at early morning. That is the whole
explanation of my presence.'

Hugo nodded.

'I guessed as much,' he said. 'I will help you if I can. But first tell
me what happened in the flat last night after Miss Payne entered while