Hell and Step On It — Kyt Dotson

Cab driver, Vex Harrow, picks up a strange passenger during one of her late night fares and discovers there's more to him than there seems when he vanishes mid-trip. The resulting investigation into the strange disappearance of the young boy and the general squalor of the area she picked him up in, and his story lead to an interesting, although sad discovery.

This is a short story from the Mill Avenue Vexations canon.