You re-equip your GUN so you can blow a hole in the lock to open the door.
It looks like your GUN only has 1 BULLET(S) left. Are you sure you want to use it in this way? You might need it in case you have to off yourself later.
Hey check it out. Every week we'll be revealing some new troll characters from Hiveswap until Act 2 is out. Follow the Troll Call here, and meet the first two here. Expect a few more surprises like this to drop in coming weeks.