Bowels

The house was unpleasantly warm and damp, like a greenhouse or a sauna. It reeked, too, even outside of the basement. We conducted the investigation as thoroughly as we could, under the circumstances.

"Jeez, how long have these been here?" The bones were barely covered with a slimy, soupy mess. You couldn't even tell they were bodies.

"According to their neighbors, they were seen out and about two days ago."

"But these... I mean, they've been rotting for weeks, at least."

"Or..." I hesitated. "Or digesting for about twelve hours."

The house groaned, then. I refuse to say it belched.