The "piece" referred to in the context of this episode often relates to . In this finale, Lucy goes undercover as a "chemist" for a drug syndicate to manufacture illegal "product" (a "piece" of high-value criminal operation). Key Plot Points of 3x14 "Threshold"
, titled " Threshold ," is the season finale of the third season , which originally aired on May 16, 2021. The Rookie 3x14