in a grip or a sack or something like that, yet the
bank record shows that no one but Trier entered with a grip and no one
left with a package for ten minutes before Trier entered."

"There may be something in what you say, Carnes, but I am inclined to
have a different idea. I don't think it is the usual run of bank
robbery, and I would rather not hazard a guess just now. I am going back
to Washington to-night. Before I go any further into the matter, I need
some rather specialized knowledge that I don't possess and I want to
consult with Dr. Knolles. I'll be back in a week or so and then we can
look into that counterfeiting case after we get this disposed of."

"What am I to do?" asked Carnes.

"Sit around the lobby of your hotel, eat three meals a day, and read the
papers. If you get bored, I would recommend that you pay a visit to the
Art Institute and admire the graceful lions which adorn the steps.
Artistic contemplations may well improve your culture."

"All right," replied Carnes. "I'll assume a pensive air and moon at the
lions, but I might do better if you told me what I was looking for."

"You are looking for knowledge, my dear Carnes," said the doctor with a
laugh. "Remember the saying of the sages: To the wise man, no knowledge
is useless."

* * * * *

A huge Martin bomber roared down to a landing at the Maywood airdrome,
and a burly figure descended from the rear cockpit and waved his hand
jovially to the waiting Carnes. The secret service man hastened over to
greet his colleague.

"Have you got that truck I wired you to have ready?" demanded the
doctor.

"Waiting at the entrance; but say, I've got some news for you."

"It can wait. Get a detail of men and help us to unload this ship. Some
of the cases are pretty heavy."

Carnes hurried off and returned with a gang of laborers, who took from
the bomber a dozen heavy packing cases of various sizes, several of them
labelled either "Fragile" or "Inflammable" in large type.

"Where do they go, Doctor?" he asked when the last of them had been
loaded onto the waiting truck.

"To the First National Bank," replied Dr. Bird, "and Casey here goes
with them. You know Casey, don't you, Carnes? He is the best
photographer in the Bureau."

"Shall I go along too?" asked Carnes as he acknowledged the
introduction.

"No need for it. I wired Rogers and he knows the stuff is coming and
what to do with it. Unpack as soon as yo