What do you do when an alleged serial killer escapes from captivity? If you're Jerry Bruckhiemer, you answer that question with a CSI crossover episode that takes two CSI teams to solve the case.

Henry Darius, the accused killer, has been flown into Miami from New York after promising to show the cops where one of his victims is. When the plane lands, though, it is spotted by four young adults who realize the plane is flying too low and suspect their help is needed. Darius kills all four plus the pilot, by gunshot.

Horatio Caine (David Caruso), the head of Miami's CSI team, could use a little help solving the case. Enter Mac Taylor (Gary Sinise), in charge of the CSI division of NYPD. Taylor is also the cop who originally arrested Darius.

These two are very different. Horatio is rugged, both from years of being a cop and having to deal with family issues. Ray, Horatio's brother, was presumed dead at one point. Being a cop, the suggestion of malfesance was simple to accept. Neither of those two assumptions were true. Ray "disappeared" after getting in over his head trying to help out federal agents. Horatio cooked up a plan to reunite his younger brother with Yelena (Sofia Milos), Ray's wife, and Ray Jr. Unfortunately, Horatio had to tell Yelena that Ray fathered a child out of wedlock.

Mac is hardened by both the Streets of New York and service in the Marine Corps. Originally from Chicago, Mac transferred to NYPD. As a CSI director, Taylor runs a tight ship. Aiden Burn (Vanessa Ferlito) found that out when she was fired for opening a sealed envelope containing evidence, i.e. tampering. Under that exterior, Mac genuinely cares about his team.

Lindsay Monroe (Anna Belknap), the CSI from Montana who replaced Aiden, is slowly becoming a valued member of the team. After enduring as much teasing from Denny Messer (Carmine Giovanzzo) as she can stand, she asks him if he knows that she has seen a bad crime scene before. He says, "No I don't, actually I don't. Have you?" She replies that she has, and it was a lot worse.

After Darius takes a private plane back to New York, Horatio flies up to assist. Before Darius is captured, twelve people are dead in the course of seventy-two hours. In an odd twist, Darius kidnaps and kills one of his two half sisters.