They are marching in a desperate mob. Zacharias grits his teeth, struggling to be patient and failing. He has to be out of here before the battle starts.
He has to get back to his family. They're worried about him, they're terrified of losing him, and since he has no faith in Potter he desperately wants to see them before the end of everything.
Zacharias thinks of the idiots who stayed behind—some from his own house (his stomach lurches with fear at the thought of what might happen to what he considers his other family). He remembers the questioning eyes of his yearmates, many of whom held their places at the table while the other students desperately pushed behind the Ravenclaws. They were willing to throw their lives away for a 'noble' cause. And as much as it is killing him inside not to go back, to try and reason and beg them to return with him, to do everything in his power to protect them even if it means staying and fighting himself, he doesn't do it.
Because Zacharias sees through the masquerade, he understands what's really going on. He knows that this isn't a matter of good and evil, that the Death Eaters and the Order are irrelevant, that the epic battle on the brink of unfolding is really only between the two wizards responsible for Cedric Diggory's death.
And Zacharias does not give a damn about either of them. He is not going to die for them.
Unable to stand it anymore, he begins to push and shove his way to the front, knocking down girls, first years, anyone in his way.
