Thmyl-ttbyq-layk-stwry

Forward ROT-1: t→u, h→i, m→n, y→z, l→m → uinzm (no). Given the symmetry of the groups (5 letters each), maybe it’s a encoded by a simple cipher. But without a key, best guess: This is likely from an ARG or puzzle where the solution phrase is “The mystery lake story” or “The Mill by the Lake Story” — but incomplete.

It looks like you’ve provided a string of letters and hyphens: thmyl-ttbyq-layk-stwry

Try: thmyl → sglxk (nope) (shift each letter back by 1): t→s, h→g, m→l, y→x, l→k → sglxk (no) Forward ROT-1: t→u, h→i, m→n, y→z, l→m →

Or if it’s a title: