In an abandoned New York City parking lot, a suspected kidnapper named Lucas is tossed in the back of a sedan, joined by gritty detective Robert T. Ironside. He presses Lucas for the location of a missing girl as his partner Virgil shouts out his rights. Ironside unleashes a litany of verbal and physical jabs that force the man into a confession and lead to the girl's rescue. Captain Ed Rollins lets Ironside know he's lucky - he doesn't like the detective's methods, but he can't argue with the results.
In a flashback, a pre-wheelchair Ironside and his partner, Gary, dangle a perp off a building rooftop for info. The perp gives in and his intel leads them to a restaurant and an intense chase into an alley - where Ironside is shot in the back and paralyzed. Ironside comes out of the flashback in a fit of rage, lifting weights and trying to blow off the anger pent up inside of him.
On a downtown sidewalk, Annie Ryan lies face down in a pool of blood, suspected of jumping from the building's roof. Ironside questions her boss, Bill Broughton, at the financial firm where she worked, but leaves with nothing except a suspicion that the two were lovers. Later, Robert searches through Annie's desk and finds a locket containing a photo of her sister, Rachel.
Trusting his gut, Ironside opens a homicide investigation and instructs his elite team of investigators, Teddy, Virgil and Holly, to dig deeper. Teddy and Virgil inspect Annie's apartment and find a box full of racy photos of Annie, an odd detail for a broker. Holly taps a mob informant for his take on the photos and he recognizes the type - sex-fueled "flower parties" where rich finance execs play Caligula. One of the girls in the photos belongs to an Albanian...
Meanwhile, Ironside questions Annie's sister, Rachel, who reveals that Annie hated her co-workers and suspects they led her to her death. Annie's trainer, Amanda, feels differently and points the team to Annie's sketchy boyfriend, Zamir. But when they track down his apartment, they find Zamir with a knife in his chest... and a photo of him and Annie at a sex party.
That night, Ironside hooks up with Amanda from the gym, but an urgent call from the precinct kills the mood - his old partner Gary was arrested for disorderly conduct. Ironside bails him out and urges him to move on and stop beating himself up over the past. But Gary lacks the same will and Ironside leaves in a huff.
When the team discovers Annie that laundered her boyfriend's drug money through her job at Mullen Financial, they revisit her boss, Bill - and again he deflects any knowledge. Ironside knows this guy's holding back, but a new lead from Zamir's apartment takes priority. They pull in another suspect, Alek, and he lawyers up right away. With roadblocks in every direction, Ironside starts spitballing and right as they make some progress, Holly gets a call - Annie's sister has Bill at gunpoint inside the firm.
When the team arrives, Rachel makes it clear that she wants justice for her sister and that Bill's the center of the problem. Ironside tries to reason with her but she won't budge - so Ironside orders Holly to shoot the hostage - Bill - in the knee. She hesitates, then fires - allowing the cops to apprehend a stunned Rachel.
In the interrogation room with Bill, Ironside details how the man used Zamir's drug money to pay back a botched London deal, then used Annie as a scapegoat when he couldn't recoup the cost. Bill promises to give up Alek's role for complete immunity - and Ironside refuses, vowing to take him and Alek down. Later, Ironside confesses to Captain Rollins that knew it was a suicide all along - he just needed to figure out why Annie killed herself, so he could punish the people the drove her of the ledge.
That night, Ironside listens in on a support group meeting as Gary relives the day his partner got shot. The emotion is almost too much for Gary to bear, but it's his first time at the support group. At least he's trying to help himself now. Ironside goes home and finds Amanda waiting for him outside his house. Is she stalking him? She jokes that he better call the cops but Robert says he's off-duty as the two go inside...