As he stole down the alley-way Jack Benson was too sensible, and by this
time, too much experienced in the ways of a rougher world, not to suspect
that there might be some trap in that door partly open. "He may have
seen me, and may have left that door open on purpose," Benson reflected.
"He may be lying in wait for me, inside. Or else he may have left that
door open, just to make me suspect a trap and keep out. In the meantime,
he may be slipping through a door on the other side of the house, and
sneaking away from me."

For a few seconds Jack Benson paused thoughtfully on the step just
outside the door that was partly ajar.

"I may walk into a trap, by going inside, or I may be letting that
wretch walk out of one by staying out here," wavered Benson, torn
between two impulses.

Then, just as suddenly, this thought flashed through his mind:

"What you're doing is for the Flag! Never mind what happens to you,
Jack Benson. Just rash in and say '_here goes_'!"

There was not another second's hesitation. Jack Benson softly pushed
the door far enough open to admit him. At the back of the hallway he
saw stairs leading below.

"Basement stairs, with a rear basement door letting out on another
alleyway!" suspected the submarine boy.

Though he had determined to be as reckless as seemed necessary in order
to get quickly on the trail of the vanished one, Jack moved on tip-toe.