Una piedra en el zapato
Police procedural: some detail pertaining to a murder case is nagging at the back of a detective's mind "like having a stone in his shoe." Once he teases it to the surface, he solves the case.
Police procedural: some detail pertaining to a murder case is nagging at the back of a detective's mind "like having a stone in his shoe." Once he teases it to the surface, he solves the case.