In The Rookie 5×21 “Going Under” Lucy will return to her undercover job, dealing a setback for Chenford if the previous episode is any indication. At the end of The Rookie 5×20 “S.T.R.” Tim was trying to convince himself and Lucy that her following her call to go undercover wasn’t a problem for him nor would it be for them.
Now, in The Rookie 5×21 “Going Under” those words will be put to the test when Lucy once again infiltrates a dangerous operation. So we could say that this episode feels like a continuation of the previous one as far as Chenford is concerned.
This will stir the hornet’s nest for them and the conflict that began to brew last week will begin to explode this week. But no matter what, they’re endgame and that’s just facts.
For their part, Nolan and Harper team up again for a rather dark case in The Rookie 5×21 “Going Under.” Some amputated members appear in the city and the old partners will be in charge of putting together the pieces of the macabre puzzle.
Here are the two pictures — yes, two — for The Rookie 5×21 “Going Under”:

(ABC/Ser Baffo) MELISSA O’NEIL

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.
Here’s the promo for the episode:
The Rookie Season 5 airs Tuesdays at 8/7 on ABC.