The only reason Julien managed to find Alfie after all that was because he flung a tracking spell Alfie's way just before the other boy disappeared down a stairwell and out of sight. Although he wasn't unfit per se, Julien was a bookish type, didn't like to even venture outside most of the time and thus had no way in hell of keeping up with Alfie, longer legs and all.
By the time he'd literally tracked the boy down he saw him huddled up and sobbing, the sight immediately making an echo pang of pain in Julien's chest. He approached tentatively, unsure if his presence would be wanted anymore considering what he'd done, the boundary he'd broken through... but Alfie was so miserable, Julien couldn't bear not to do what he did next. Settle himself down beside Alfie and slowly, unsurely, put a hand on his arm.