agent's house. Therefore he took it from the murdered man's
pocket."

"Good, Lestrade, very good," said Holmes. "Your theory holds
together. But if this is true, then the case is at an end. On
the one hand, the traitor is dead. On the other, the plans of
the Bruce-Partington submarine are presumably already on the
Continent. What is there for us to do?"

"To act, Sherlock--to act!" cried Mycroft, springing to his feet.
"All my instincts are against this explanation. Use your powers!
Go to the scene of the crime! See the people concerned! Leave
no stone unturned! In all your career you have never had so
great a chance of serving your country."

"Well, well!" said Holmes, shrugging his shoulders. "Come,
Watson! And you, Lestrade, could you favour us with your company
for an hour or two? We will begin our investigation by a visit
to Aldgate Station. Good-bye, Mycroft. I shall let you have a
report before evening, but I warn you in advance that you have
little to expect."

An hour later Holmes, Lestrade and I stood upon the Underground
railroad at the point where it emerges from the tunnel
immediately before Aldgate Station. A courteous red-faced old
gentleman represented the railway company.

"This is where the young man's body lay," said he, indicating a
spot about three feet from the metals. "It could not have fallen
from above, for these, as you see, are all blank walls.