How do you open the barred doors in the Binding of Isaac?
I ran into this gated challenge room during a recent Binding of Isaac playthrough (with Maggie, as you can see). I had definitely killed the enemies in the room as the entrance door reopened but this one did not. I've been able to enter challenge rooms before without much fanfare. Is there something extra I have to do to open this door? Is Maggie not allowed in weapon rooms?