Day 1,871

We'd been so busy working our way through the colossal rusted ruins, which were still mostly buried deep beneath the earth, we never considered that beneath the thick layer of rust there was bone. In fact it was safe to say that if we hadn't reached the mouth we'd never have known it was a creature at all.

Natural iron had coated the giant remains so thoroughly it took us a few months to recognise that most of the stalactites were actually teeth. From there we began to scan and chart the rest of the creature until we'd come up with enough to understand what we'd been building and living in.

It had been over 400 feet in length when it was alive, judging by the high nitrogen properties in the soil that indicated something had died and decomposed there. We were so fixated on the skeletal remains that we completely ignored the signs that there had been others.

That was, until they woke up.