Bedivere and Dito (kusattaniku) will be searching for any doors that seem to have unusual odors or sounds emanating from within. They'll also be looking for doors bearing scratch or puncture marks, maybe blood? Dito has experience picking locks, and his Acata ability is forming eyeballs, so if there's some open space underneath or around a door, he could roll in an eyeball and take a look around? He could also generate one to look into a small or awkward angle. Bedivere, meanwhile, can offer some good old-fashioned strength. They'll be willing to keep at this for pretty much as long as possible.