"Hardly," added Mark.

"No, I guess he is still on the Red Planet, so it couldn't have been
him," went on Mr. Roumann. "But it was some one."

Jack and Mark at once thought of the odd man who had sent Mark the
note, and then had run away.

"Could it have been him?" suggested Jack.

"It's possible," remarked Professor Henderson. "We must be on our
guard. I wonder if Washington----"

At that moment there sounded a violent pounding on the exterior of the
projectile, and the voice of the colored man could be heard calling:

"Am anything de mattah? Andy Sudds an' I is out heah, an' we heard
suffin goin' on in dere. Am anybody hurted?"

"It's all over now, Wash," replied Jack, for the two boys, and the two
professors, had shut themselves up in the projectile while they
conducted the experiment. Jack opened the door of the _Annihilator_
and stepped out, being met by the colored man and the old hunter.

"You haven't seen any suspicious characters around, have you, Wash?"
asked Mark. "Some one has been tampering with a motor, and it
exploded."

"Nobody's been around since I've been here," announced Andy Sudds, with