"How could any one get there?"

"There's a trap-door at the end of the passage," exclaimed Shepherd. "Quick! we shall cut him off."

A rush was made for the door, but it refused to open; some one had evidently blocked the exit from the outside, by placing a short form lengthways across the passage. The drawing classroom formed part of a one-storied building which bounded one side of the school quadrangle. Finding the door closed, Shepherd dashed to the nearest window, and flinging it open dropped out on to the gravel, an example which was speedily followed by the chairman and several members of the audience. Breathing out all manner of threats, they ran round through the nearest door and gained the entrance to the passage. The trap-door in the ceiling was wide open, and communicating with it was a curious, home-made ladder, consisting of an old post, with half a dozen rough cross pieces fastened to it with stout nails. A candle end was lying on the floor, and with its aid Shepherd climbed up and explored the roof; but the bird had flown.

After such an interruption it was no use attempting to continue the debate, and Redbrook and his companions spent the remainder of the evening trying to discover the authors of this outrage.

The culprits, however, had made good their escape; no one remembered having seen the ladder before, and it was impossible to say to whom it belonged. The members of the debating society were clearly outwitted; and not wishing to make the story of their discomfiture too public, they determined for the present to let the matter drop, at the same time announcing their intention of taking dire vengeance on any irreverent jokers who should rashly attempt to disturb their meetings in future. Two days later, Valentine was sitting at his desk reading, when he was joined by his cousin.

"I borrowed your brass ruler the other afternoon," said the latter, producing something from under his coat.

"Yes, I know all about it, you villain!"

"I only used it as a sort of pea-shooter."

"Oh, I've heard all about your little game; Preston told me."

Jack tried to look innocent, and then laughed.