And then, all at once, it came over him that it did not matter what Ernest answered, that there could be no reasonable and good explanation for what he had caught Graves doing.

“You sneak!” he cried.  “What are you doing here —­ spying on us?”

He sprang forward, and Graves, with a snarling cry of anger, lunged to meet him.  Had he not been handicapped by his lame ankle, Harry might have given a good account of himself in a hand-to-hand fight with Graves, but, as it was, the older boy’s superior weight gave him almost his own way.  Before Jack, who was running up, could reach them, Graves threw Harry off.  He stood looking down on him for just a second.

“That’s what you get for interfering, young Fleming!” he said.  “There’s something precious queer about you, my American friend.  I fancy you’ll have to do some explaining about where you’ve been tonight.”  Harry was struggling to his feet.  Now he saw the papers in Graves’ hand.  “You thief!” he cried.  “Those papers belong to me!  You’ve stolen them!  Give them here!” But Graves only laughed in his face.

“Come and get them!” he taunted.  And, before either of the scouts could realize what he meant to do he had started one of the motorcycles, sprung to the saddle, and started.  In a moment he was out of sight, around a bend in the road.  Only the put-put of the motor, rapidly dying away, remained of him.  But, even in that moment, the two he left behind him were busy.  Jack sprang to the other motorcycle, and tried to start it, but in vain.  Something was wrong; the motor refused to start.

“That’s what he was doing when I saw him first,” cried Harry, with a flash of inspiration.  “I thought it was Dick, trying to start his motor —­ it was Graves trying to keep us from starting it!  But he can’t have done very much —­ I don’t believe he had the time.  We ought to be able to fix it pretty soon.”

“It’s two miles to the repair place!” said Jack, blankly.

“Not to this repair shop,” said Harry, with a laugh.  The need of prompt and efficient action pulled him together.  He forgot his wonder at finding Graves, the pain of his ankle, everything but the instant need of being busy.  He had to get that cycle going and be off in pursuit, that was all there was to it.

“Give me a steady light,” he directed.  “I think he’s probably disconnected the wires of the magneto —­ that’s what I’d do if I wanted to put a motor out of business in a hurry.  And if that’s all, there’s no great harm done.”

“I don’t see how you know all that!” wondered Jack.  “I can ride one of those things, but the best I can do is mend a puncture, if I should have one.”

“Oh!” said Dick, “it’s easy enough,” working while he talked.  “You see, the motor itself can’t be hurt unless you take an axe to it, and break it all up.  But to start you’ve got to have a spark — - and you get that from electricity.  So there are these little wires that make the connection.  He didn’t cut them, thank Heaven!  He just disconnected them.  If he’d cut them I might really have been up a tree because that’s the sort of accident you wouldn’t provide for in a repair kit.”