"Is Mr. Spielhagen sure that the missing page was with the others when he sat down in the adjoining room to read his thesis?" asked their perturbed host.

"Very sure," came the emphatic reply. "Indeed, I was just going through the formula itself when I fell asleep."

"You are ready to assert this?"

"I am ready to swear it."

Mr. Cornell repeated his request.

"I demand that you make a thorough search of my person. I must be cleared, and instantly, of every suspicion," he gravely asserted, "or how can I marry Miss Digby to-morrow?"

After that there was no further hesitation. One and all subjected themselves to the ordeal suggested; even Mr. Spielhagen. But this effort was as futile as the rest. The lost page was not found.

What were they to think? What were they to do?

There seemed to be nothing left to do, and yet some further attempt must be made towards the recovery of this important formula. Mr. Cornell's marriage and Mr. Spielhagen's business success both depended upon its being in the latter's hands before six in the morning, when he was engaged to hand it over again to a certain manufacturer sailing for Europe on an early steamer.

Five hours!