Jack was about to clasp his chum in his arms when he saw that Mark's
arm was in a sling, and that his face was all bandaged up, so that
scarcely any of his features showed. Had it not been for the clothes,
and a certain stoutness of which Mark never could seem to get rid, Jack
would scarcely have known his friend.

"Why, Mark, what happened?" cried Jack. "Have you met with an accident?
Where have you been? In a hospital? What became of you? Why didn't you
wait for me?"

"I can't answer all those questions at once," was the reply, and Jack
thought Mark's voice was curiously muffled and hoarse, entirely unlike
his usual tones. But he ascribed that to the bandages around the mouth.

"Well, answer one at a time then," said Jack, and there was an
undefinable, strange air about his chum which cooled Jack's first
impulse of gladness. "Whatever happened to you, Mark? Are you hurt?"

"I was--yes," came the reply, in short, jerky tones. "I had an
accident, and I've been in a hospital. That's why I couldn't send you
word. But I'm all right now. When does the projectile start?"

"To-morrow, now that you're here. But tell me more about it. Where were
you hurt?"

"On my head and arm."

"No; I mean where did the accident occur?"

"Oh, in the old house where I went to--to look for that man."