Picking up where "Hostage" left off, the team is frantically searching for Mac Taylor, who manages to pull himself out of a submerged car and reach the shore--in New Jersey. Disoriented from a mild concussion, Mac waves down a woman driving by in a car and asks to use her cell phone to call Stella. Stella and Flack rush to the scene, where the New Jersey CSIs have already recovered the car--and the dead body of Derek James, the cohort of Joe, the man who tricked Mac into helping him escape. Stella and Flack walk towards mac, who is the back of an ambulance getting checked out by a medic. Though the New Jersey CSIs insist on maintaining jurisdiction over the scene, the NY team is able to take photographs. Sid does a virtual autopsy on Derek, showing Stella that the bullet that killed him entered through his cheek. Mac gets off an elevator at HQ where danny comes rushing toward him telling him shouldn't be there after getting the concusion. Mac heads to the showers where he discovers a bullet in the collar of his shirt and Lindsay offers a shocking theory: he was shot while in the car, but the round was either old or had its momentum slowed by the window of the car or the fabric of his shirt. Mac realizes Joe probably assumes he's dead. Danny shows Mac a barrette recovered from the car, and tells Mac DNA has shown that it belongs to Joe's daughter. Based on the tire treads from the car Joe took from Derek, Adam thinks Joe is back in New York--the treads aren't deep enough for the car to have been carrying two million dollars. Hawkes is able to listen to the recording from the walkie talkie that was in the car with Mac and Joe and recover the phone number Joe dialed, leading him to Derek's phone, which has Joe's number in it. Mac calls the number and tells a surprised Joe to turn himself in. Joe, on the hunt for the money, refuses.
Adam approaches Flack with some startling news: Joe was caught on a toll booth camera driving a car registered to Flack's sister, Samantha. Flack confronts his sister, who tells him she loaned it to a friend of hers named Lauren Salinas. Danny has matched the bullet from Derek's body to the one in Mac's shirt, leading Danny to think Derek shot at Mac and then went for Joe but had the gun turned around on him. Lindsay has identified material on Mac's CSI kit from Joe's shoe as being a rare plant that's sensitive to touch. After giving Flack some time to talk to Samantha, Adam shares the information with a less-than-pleased Mac. The car is recovered--with Lauren's body in the trunk. Mac recognizes her as the woman who loaned him her cell phone in New Jersey. Danny questions Samantha, who doesn't recognize either Derek or Joe but says she knows Lauren was dating someone. Flack is concerned that she's gone back to her old ways. Sid determines Lauren died of a stab wound, but also finds evidence she was tortured: water in her lungs and abrasions on her wrists. Mac suspects Joe tortured her to find out where Derek hid the money. Mac and Stella head to a field where the plant Lindsay found grows near some deserted rail tracks and discover a buried stash of passports and licenses. Joe, observing from above, calls and promises he'll beat them to the money. When Mac confronts him about Lauren's death, Joe claims it was an accident.
Adam and Lindsay examine the passports and find the real one, revealing Joe's real name as Ethan Scott. They connect the dots: Lauren was a teller at the bank, and trace from Derek's throat indicated he swallowed a key. The CSIs realize the money is still at the bank in a safety deposit box. Stella rushes there, only to find Ethan with the money in hand. Stella chases him to the roof, where he throws her off the side of a railing and, as she scrambles back up, escapes. The CSIs have linked Ethan's tax records with those of his wife and daughter: Allison and Emma Scott. Adam discovers three train tickets to Canada purchased with Allison's credit card. Stella confronts Allison at the train station and tells her what Ethan has done, trying to enlist her help. A few hours later, Ethan arrives at the train station to meet his wife and daughter. He gets a phone call from Mac but is sure he's in the clear--until Mac appears behind him and places him under arrest.