[s7e3] The Fisher King -

If you specifically meant Season 7, Episode 3, the "piece" of evidence crucial to that case involves:

Spencer Reid is cast as "Sir Percival" and is given the task of asking the question that will "heal" the King. Context for S7E3: " Dorado Falls " [S7E3] The Fisher King

In this storyline, the Fisher King lures the team into a "quest" for the Holy Grail by sending them individual clues or physical items. If you specifically meant Season 7, Episode 3,

Each team member receives a personal item or message while on vacation that leads them back to Virginia. The team has to piece together his military

The team has to piece together his military background and the specific trigger of a car accident to stop his mass murder spree at an internet security company. "Criminal Minds" The Fisher King: Part 1 (TV Episode 2006)

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.