“Come here, Carl!” called the stoop-shouldered one, in a low voice.

From another clump of bushes came another man, bearded and bespectacled.  If there’s anything in a face, Carl was unmistakably German.

“Carl will tell you what to do,” said time stoop-shouldered one.

“You men are in two different companies?” asked the man behind spectacles.

“I’m in B company,” nodded Mock.  “Wilhelm is in E company.”

“Then you can take care of two companies of men,” Carl went on.  “Do to-morrow morning what I’m going to tell you.  See these?”

The bespectacled one held up two vials that he had taken from a pocket.

“Each one of you takes one of these,” he went on.  “Hide them to-night where you please.  In the morning, when the men in your barracks hang their bedding out of the windows and go down to breakfast, stay behind.  Uncork a vial, each of you, and sprinkle the liquid in here on the bedding of at least half a dozen soldiers.  You understand?  Then slip down to your breakfasts.”

“What’s in these vials?” asked Mock, taking the one offered him and curiously inspecting the liquid in it.

“Germs!” said the bespectacled one.  “Measles.  Do as I tell you, and in a few days measles will begin to run through the two companies like wildfire.  In a few days more it ought to be well through the regiment.  Tomorrow night slip out of camp and come here.  Under those bushes over there you’ll find civilian clothing.  Understand?  Yes?  In the pockets of each suit you’ll find the money to pay for your work.  Take off your uniforms and put on the other clothes.  Then go where you please, but be sure to keep out of time Army after this, for American soldiers are going to die fast!  The money you’ll find will take care of you.  Yes?”

“Yes!” nodded Mock.  “Sure!”

Then, suddenly, Mock turned and whistled.

“You two men will throw up your hands!” came in the sharp tones of Captain Dick Prescott, as he, Sergeant Kelly and four privates stepped into view.

“You sneak!” yelled the stoop-shouldered one, making a rush at Mock and trying to seize the vial.  But Mock dodged.  In the same instant the bespectacled German tried to snatch the other vial away from Wilhelm, but that soldier, too, dodged and saved the vial.

“On the ground is a good place for you!” growled Sergeant Kelly, knocking the stoop-shouldered stranger flat.  Then, before the fellow could rise Kelly had snapped handcuffs his wrists.

Two of the soldiers seized the bespectacled German just as he started to run.  He, too, felt the clasp of steel around his wrists.  Though Kelly and the four privates were armed with automatic pistols no weapon had been drawn.

“Twice you’ve played the sneak, you!” hissed the stoop-shouldered one, glaring at Private Mock.

“Twice more I’ll do it to help Uncle Sam,” retorted Mock, with a short laugh.  “I owed it to you to see you caught!”