Grace's childhood memory of unlocking a forbidden drawer and finding a pistol gives way to her asking Ro to deliver painkillers, then placing the bullet she extracted from her thigh into a pill bottle.
Meanwhile, Moretti and Franco meet with mob boss Titus Amato, who refuses to give the business that's been awarded to Constantine back to Moretti - so Moretti orders Franco and a group of thugs to break into Constantine's warehouse and destroy his gaming machines.
But when they do, the machines aren't there, and Constantine's thugs emerge from the shadows with guns blazing. Franco escapes in a hail of bullets that pepper a passing car, wounding the driver, Paige Wilson, and her passenger mother, Ann.
After Ro delivers the painkillers to Grace, the hospital summons Ro to deal with incoming multiple gunshot victims. Grace follows Ro to the hospital, where Fleming performs surgery on Ann. Afterwards, Grace asks Ann for permission to remove a bullet in Paige's brain, explaining that the procedure could leave Paige crippled - or the problem could be treated with anticlotting medicine. Ann chooses the latter. And Brett tells his patient - Constantine's thug, Gio - that he'll be OK, but the bullet in his leg can't be removed.
FBI agent York confronts Constantine, then Gio, about the shootings. When they refuse to cooperate, York asks Grace to pass along anything she knows. Ro and Brett also want Grace to explain her situation. She refuses, then learns that the medicine failed and Paige died. When Grace tells Ann what happened, she blames Grace. She later apologizes for this.
Meanwhile, Constantine and crew find Moretti at a cafÃ© and ask him for Franco's whereabouts. When Moretti refuses, Constantine pins Moretti's hand to a table with a fork and orders him to leave Chicago tonight or he's a dead man. Afterwards, Moretti orders an attack on Constantine's home.
Stafford informs Brett that the bullet in Gio's leg is now moving through his body and must be extracted immediately, which they do. When Franco tells Grace not to leave the hospital for 24 hours, she tells him to get - and stay - lost. Then Brett gives Grace the news about Gio and again asks her to confide in him. Again, she refuses.
After Stafford tells Grace a coroner's examination of the bullet in Paige's body might reveal her killer, Grace confesses her mob involvement to Ro and enlists her help in removing the bullet from Paige and switching it with the bullet Grace extracted from her own leg.
As Moretti and his gang are about to attack Constantine's home, they're surrounded by FBI agents. York takes Moretti's gun and charges him with murdering Paige. Afterwards, Constantine expresses his gratitude to Grace, who demands he take care of Paige's mother for life in return. Constantine agrees, noting Grace is "a real natural at this."
Grace flashes back to her father finding the once-hidden pistol - which belonged not to him, but to her mother - then beating her mother. Grace says this taught her not to make assumptions about anything or anyone.
Meanwhile, York meets with Franco to assure him that his cover wasn't blown. When Franco wants to continue his undercover work, York refuses, saying Franco's either fallen for the criminal life or someone connected to it, and Franco needs to disappear.