Edmund is pacing.
Tom hasn't tried anything lately. It's suspicious. It's deeply, profoundly suspicious - they'd been at Hogwarts a day and a half when he drugged Edmund and ripped every secret from his mind, that's not someone who just stops doing things for a bit. Especially not when he's just been thwarted. So Edmund is pacing.
I need to know why Tom's like this. I need to know what he wants. I need to know who he is.
...that door wasn't there before.
Edmund - hesitates for a moment, then turns the handle. He's never felt particularly threatened in Hogwarts - at least not by Hogwarts.
The door lets out... in a loo. A girls' loo. He steps inside cautiously and lets the door close behind him.