There was a still further delay and then another voice asked: "How do we know it is an officer?"
"Open and find out, before I force the door."
There was a still further delay.
"It's a good thing we guarded the rear," said Donald. "They are evidently trying to gain time to spirit Lieut. Grimes away, thinking it is Gen. Funston."
"True," said the officer. "We'll wait no longer. Corporal, force the door!"
The corporal placed a small stick of dynamite under the door and fixed a fuse.
"Step back a little," he said.
All obeyed, when at the instant the door was thrown open and a hand, in which was an automatic revolver, was thrust out, directly in the face of the officer.
But quick as was the action, Donald was not taken off his guard.
With a single swift blow he struck the weapon into the air.