"Columbus and his egg once again," said Merrick grimly. "Well, what are you going to do next?"
"To drive to Marshminster, and find out the movements of Felix on the night after the murder."
"Quite so; but first satisfy yourself on the subject of Francis."
"What do you mean?" I asked.
"What day of the month were you at the Fen Inn?" continued Merrick.
"On the 10th of June."
"Good! Francis there told you that he had just arrived from Chili. Now, find out what boat he came by, look up his name in the passenger list, and ascertain the date on which the true Francis arrived in England. That point established, you can prove the false Francis to be an impostor."
"An excellent idea," said I, starting to my feet. "I'll see about it at once."
"And mind," said Merrick, raising his forefinger, "I expect to be kept fully advised of the case."
"Never fear, doctor. You are excellent at solving puzzles. When I find another nut, I'll bring it to you to crack."