Maybe the dog was already on his way back, to pick up John's own trail.

They simply had to go back, pick up his trail, and stay with it They'd get him.

Instead they went off toward the river, and it took him a while to pick up their trail.

And I was the one to pick up your trail.

I'm never going to be able to pick up her trail!

We might not be able to pick up their trail again.

I have an idea I'm going to pick up his trail.

His men would pick up their trail and stay on them the rest of the night.

She would never be able to pick up their trail.

Then he'll double back and see if he can pick up my trail.