[s7e3] The Fisher King -

The "piece" for the puzzle was a section of a large map or picture that, when assembled, revealed the location of his "Grail"—his daughter, Rebecca.

In the context of the popular crime drama Criminal Minds , the "piece" usually refers to the physical puzzle pieces sent by the unsub Randall Garner—the Fisher King—to the BAU team. [S7E3] The Fisher King

Each team member receives a personal item or message while on vacation that leads them back to Virginia. The "piece" for the puzzle was a section