Officer Tim Bradford’s ex-wife returns and asks the team to help her save someone from her undercover past. Isabel’s return also creates additional pressure in Lucy and Tim’s relationship as they assist in the search.

Officer Lucy Chen goes undercover to infiltrate an illegal firearm operation, and Detective Harper and Officer John Nolan work together to solve a mystery involving severed limbs found around the city.

The crossover continues on The Rookie: Feds S01E21 Bloodline (II).