When she first appears in the pilot episode, Tim tells Lucy Chen that Isabel is his wife and that he hasn't seen her in nearly a year. Isabel looks gaunt and sick and she demands money from Tim, which he gives her, and then runs off.
In "Crash Course", Tim rushes to the emergency room to find Isabel leaving after being treated for a heroin overdose. She once again refuses his help and leaves. In "The Good, the Bad and the Ugly", Tim signs out several doses of Narcan from the police station, intending to deliver it to Isabel in order to help her mitigate the effects of heroin. When he arrives at Isabel's apartment, his rookie Lucy convinces him to let her deliver it.
During Lucy's brief conversation with Isabel, we learn that Isabel was once an undercover Narcotics cop working "out of the 77th". Later Tim tells Lucy that when Isabel was staying out late and making excuses for it, he thought she was having an affair; he found out too late that she was addicted.
In "The Ride Along", Isabel is arrested for drug possession and admits to Tim that her dealer/"boyfriend" hid a kilo of heroin in her apartment. Tim goes to Isabel's apartment at night and finds the stash but does not remove it, thereby ensuring that Isabel will remain in custody, for which she resents him.
In "Time of Death", Isabel agrees to act as C.I. (confidential informant) and go undercover to a meet with her dealer's supplier, Vance. When she takes a chance to bargain with the supplier, and he disconnects her wire, her backup rushes in to find the supplier, his henchmen, and Isabel gone.
In "Standoff", Isabel is found severely injured, shot in the head, in a dumpster, and the police canvass an apartment building known as a base for Vance's crew. They find and subdue Vance and Tim assures him that when Isabel wakes up and reports on him, he'll be going away for the rest of his life. Later we see Tim at Isabel's side in the hospital when she regains consciousness.
In "Heartbreak", Tim takes a personal day off to go visit Isabel in the park. They discuss their relationship at length before Tim decides to break it off. Isabel thanks him for never giving up on her and the two separate.
|The Rookie: Season 1|
|"Pilot":||"Crash Course":||"The Good, the Bad and the Ugly":||"The Switch":||"The Roundup":||"The Hawke":||"The Ride Along":|
|"Time of Death":||"Standoff":||"Flesh and Blood":||"Redwood":||"Heartbreak":||"Caught Stealing":||"Plain Clothes Day":|
|"Manhunt":||"Green Light":||"The Shake Up":||"Homefront":||"The Checklist":||"Free Fall":|
- Mircea Monroe has appeared recently with Nathan Fillion, as videogame character "Elena" in the 2018 fan film "Uncharted".