Magnus doesn't know what to say and Alec is being utterly silent. At this point Magnus is certain that Alec wants nothing more than to go home.

Looking across the way he see's the same posters and noticed Alec staring, not only that he can't seem to take his eyes off of them.

Is Alec aware that Magnus is three hundred years old? Is Alec considering exactly how impotent one might become after that much time.\

Just as Magnus is hoping for some distraction two guys come on the train.