"If you're right then there should be a trapdoor or some kind of round cover inside the house itself. It would be of little use outside the house. The unstable weather comes frequently enough that I would not think they would carpet over it or cover it up with a display cabinet."

Yes, he is much more amenable to this idea of looking for some bumps on the floor where there should be hinges, maybe handles or latches, or some kind of unevenness for a sliding door kind of mechanism.

"Let's take a look around?" It would be quicker for them to split up but, just in case it ends up being a dangerous endeavour or needs anything heavy to be moved, it would be easier for them to stick together.