Patrolling the gaps was no one's pleasure, even less so after dark. He could see the camp lights on the surface of the water.  It all looked so far away.

A rustle of motion drew his attention and he froze in his tracks, rifle poised, searching for a target. He listened intently and waited for what he feared was there. Nothing happened. A quick scan of his surroundings settled his nerves. Then, a glimmer in the gap caught his eye.

The Irish had gone extinct.  They'd been culled by the infiltrators for reasons unknown, but due to that elimination their teeth had become quite valuable.

Paget saw an Irish tooth, sir, in a waste gap.