Billy Windsor was seated comfortably on Mr. Gooch's chest a few feet away. By his side was his big stick. Psmith possessed himself of this, and looked about him. The examination was satisfactory. The trap-door appeared to be the only means of access to the roof, and between their roof and that of the next house there was a broad gulf.
"Practically impregnable," he murmured. "Only one thing can dish us, Comrade Windsor; and that is if they have the sense to get on to the roof next door and start shooting. Even in that case, however, we have cover in the shape of the chimneys. I think we may fairly say that all is well. How are you getting along? Has the patient responded at all?"
"Not yet," said Billy. "But he's going to."
"He will be in your charge. I must devote myself exclusively to guarding the bridge. It is a pity that the trap has not got a bolt this side. If it had, the thing would be a perfect picnic. As it is, we must leave it open. But we mustn't expect everything."
Billy was about to speak, but Psmith suddenly held up his hand warningly. From the room below came a sound of feet.
For a moment the silence was tense. Then from Mr. Gooch's lips there escaped a screech.
"This way! They're up—"
The words were cut short as Billy banged his hand over the speaker's mouth. But the thing was done.
"On top de roof," cried a voice. "Dey've beaten it for de roof."
The chair rasped over the floor. Feet shuffled. And then, like a jack-in-the-box, there popped through the opening a head and shoulders.