He may have tripped on a vine he failed to see, and either broken his leg, or else sprained his ankle so badly that he can't even limp along.
I've known such a thing to happen--in fact, once I got myself in the same pickle, and had to _crawl_ two miles to a house, every foot of the way on hands and knees, because the pain was frightful whenever I tried to stand up.

Well, the chances are K.K.has had such a thing befall him." Horatio heaved a tremendous sigh, as though quite a weighty load had been taken off his chest.
"You make me feel a heap better, Hugh, when you're so positive," he hastened to admit.

"I was afraid it might be something even worse than a sprain; but never mind what I thought.

The question now is, what ought we do about it ?" "There's only one thing that can be done," Hugh told him in his customary straight-from-the-shoulder fashion, "which is for some of his chums to organize a searching party, get the old Kinkaid car out, and go up there to look over that abandoned road from one end to the other.

We'll find K.K., or know the reason why." "That sounds good to me, Hugh!" declared Horatio, always ready to follow where a bold leader showed the way; "and perhaps we may have an opportunity to discover whether there _is_ any truth about those queer happenings the farmers keep telling of whenever the old quarry is mentioned in their presence." "We'll not bother our minds about fairy stories," Hugh assured him.
"What we're meaning to do is to look for a practical explanation of K.K.'s holding out.