"Pooh!" answered Diggory, "how about that cipher note that said,
'To-night'?"
"Of course," added Jack Vance, "they'd evidently arranged it beforehand, and that paper was to say when they were to do the trick."
It seems possible sometimes to come by wrong roads to a right conclusion; and though the boys were mistaken in changing from their first opinion as to the meaning of the note, yet in this instance their error caused them to hit the right nail on the head.
"It was one of Thurston's lot who did it," repeated Diggory decisively; "neither Oaks nor Allingford would ever dream of doing such a mad thing."
"I don't see exactly how you can prove it," said Jack Vance thoughtfully; "that one word 'To-night' might mean anything."
"Of course it's no proof in itself," answered the other; "but what I mean to say is, that if the doctor, or any other sensible chap, knew all we do about the cipher, and what they said at their last meeting, he wouldn't doubt for a moment but that it was one of them who screwed up Grice's door. Travers says the doctor has sent for Oaks and old Ally; it'll be an awful shame if they get into a row."
"I don't see how they are going to get out of it," sighed Mugford.
"Then I do," answered Diggory stoutly, with a sudden flash in his bright eyes: "the Triple Alliance can get them out!"
"How?"
"Why, we must tell all we know, and show Dr. Denson the note."