Holcombe took the bag from the engineer sub's hands and made his way to the carriage occupied by the last speaker.
"What do you make of this, sir?" he inquired. "We fancy it belonged to a Staff Officer—the one with a St. Bernard, you may remember—and he's left the train since we've been here."
The lieutenant examined the exterior of the derelict with rapidly increasing interest.
"Hang it all!" he exclaimed; "I'll take all responsibility. Here goes."
And with a powerful heave he hurled the bag over the edge of the bridge.
Seven seconds later a terrific crash rent the air. The pungent fumes of acrid-smelling smoke eddied between the lattice-work girders.
"Thought as much," remarked the lieutenant with a cheerful grin on his bronzed features. "Yankee troop train due about now, eh? Only waiting until we were clear of the bridge? Lucky for us we are over the centre of the span, or that stuff might have given the piers a nasty jar. Staff Officer, you said?"
"Yes, sir," replied Holcombe.
"Beat up a dozen hands," continued the lieutenant briskly. "I'll bear the brunt if they are left behind. We'll see if we can run this mysterious Brass Hat to earth. I say, Curtis," he added, turning to the engineer-commander, "he's had at least five minutes' start. Bet you a box of De Reszke's we catch the chap within an hour."
"Done," replied the other.