We begin in Kobane, Syria, where a woman wearing a black niqab escapes down a rickety wooden trap door, searching for safety. She pulls her face covering off and secures a phone, dialing shakily.

At the CIA/SOCOM Forward Outpost, Joe and her team are monitoring activity. Joe's emergency phone rings, and the woman from the trap door says her cover's been blown, explaining they saw a small tattoo she has of a cross. Joe rushes into action, but the enemy fire starts before she can get her team moving for a rescue.

Joe tries to collect all the information she can but realizes there's no safe way to get her undercover asset out quickly and calls off the rescue. In the distance, a mushroom cloud explodes over a building, and Joe must reconcile with her role in losing a team member.

Four years ago, a woman is flipping burgers over a grill plate in the back of a Tast-ee Freeze in Oklahoma City. Her name is Cruz Manuelos, we learn when she gets home, passing out food to the many people in her home, including her boyfriend. He's quick to name-call, and when Cruz gets into it with another woman in the house, he quickly punches her in front of everyone to keep her quiet. Cruz apologizes, shocked, and heads to bed in tears.

Cruz escapes from the relationship the following day, but not before cracking her boyfriend across the face with a frying pan. The man chases Cruz for blocks in his underwear, and to get away from him, Cruz dives into the first storefront door she finds open, which happens to be a recruitment office for the US Marines. She speaks to the recruitment officer, and things seem promising.

Cruz falls homeless and continues working at the Tast-ee Frreeze, being watched by her ex-boyfriend and his friends. When her boss calls the cops about their looming presence, Cruz is told to file a restraining order and brought to a women's shelter for the night. She decides to change her life, signing up for the Marines. She's shown to work harder than the other trainees throughout her testing and boot camp.

Cruz's Sergeant and his superior call in Cruz after testing higher than some of the men in her training group and ask about her background. We learn that Cruz's mother died in her junior year of high school, and she's never known her father. The only family she's got left is a brother in prison since her other brother has died.

Cruz is asked if she'd be willing to walk away from the life she's known up to this point to become someone the Marines can call on. Cruz agrees, explaining she has no life to walk away from.

In the present, Joe is debriefing Donald and Kaitlyn at the CIA Headquarters in Langley, Va, about her compromised asset. Joe explains that she didn't know about the tattoo, and Donald quickly grows frustrated, angry that Joe hadn't strip-searched the asset. He leaves, and Kaitlyn advises Joe to start from scratch with another asset, reassuring her that what happened isn't Joe's fault.

Joe heads home to surprise her husband, Neil, and their daughters, Kate and Charlie. Their reunion isn't exactly a welcome one, with tension coming from everyone but Charlie, the youngest.

Joe leaves her family to eat and heads out into the backyard, where Neil follows and advises that everything is easier on the family if she calls before dropping in unannounced. Joe says she's home unexpectedly and can't divulge any further details of her job to her family, and though Neil is happy to see her, there's a distance between Joe and everyone else that they can't bridge.

Neil and Joe talk about their relationship's state after the kids go to bed. Neil asks if Joe is seeing anyone, and both share that they're not seeing anyone seriously, but it's clear they have an open relationship. They still love one another, despite the lack of Joe's presence.

Joe heads out to scout a new asset at Fort Bragg and is immediately shown Cruz, who impresses her by taking down a man twice her size. Cruz meets Joe and seems excited, but Joe is still undecided on whether or not Cruz will be the new asset.

Joe shares what the Lioness operation does, explaining that it has evolved into her team getting in with high-value targets' wives, daughters, and girlfriends. Operatives are placed into situations where they get close to the women, and the team can use that information to take the targets down from within. She asks Cruz if she can handle the morally gray area they operate in, and Cruz is on board. Joe still isn't sure.

She has Cruz strip down to ensure she has no tattoos, and though Cruz's attitude is uncompromising, Joe seems pleased. She tells Cruz to get packed, as they'll leave for a new operation the following day.

Joe briefs Cruz on their new target as they fly to Kuwait and shares her mark, the target's daughter. Cruz struggles with the lack of personal details shared between herself and Joe, but Joe advises Cruz to trust her.

Cruz is introduced to Joe's crew, meeting Bobby, Two Cups, Tex, Randy, and Tucker. Cruz drinks with the team after they push her to do so and wakes up the following day hungover. Joe is uncaring, as it's time to move. She gets dressed, and the two head out, Joe walking Cruz through her cover again in the car. Cruz is nervous, as she doesn't know the mark's name, but Joe explains she's meant to go into this blind.

The drop-off happens quickly, and though Cruz is nervous, she meets the mark, Aaliyah Amrohi, without missing a beat. The two head to shop together after Cruz makes an impression, with Joe watching in the distance, keeping the team informed.