Tommy, however, knew enough of war to be aware that there was some reason for Jim's sudden disappearance; and he presently detected a slight movement among the hawthorn bushes at the back of the fort, and guessed at once that, under cover of the noise that Drusie and Helen were making, Jim was creeping up with the intention of rescuing him. And Hal had probably allowed himself to be taken prisoner on purpose to distract attention from this manoeuvre.