Well, if the door won't open than I see three good choices for Nia to pick from.
Choice #1: Blow up the door.
Choice #2: Melt the door unless it is made of wood then just burn the door down.
Choice #3: Weld the door shut if it is made out of metal.
Just kidding
@Slayah: there are stories of tommy and dake's children as adults and one of the getting married so she has planned her stories very well and the current comics just cover the time gaps between her original comic and some of the shorts she has done of the future but she has edited a few things here and there.
Author Comments
http://paradoxicaldickery.tumblr.com/image/120143557030 Spoilerly for what they look like as adults, obviously.
Comments
Choice #1: Blow up the door.
Choice #2: Melt the door unless it is made of wood then just burn the door down.
Choice #3: Weld the door shut if it is made out of metal.
Just kidding
Or are you the one heating it...