When Det. Don Flack (Eddie Cahill), Det. Stella Bonasera (Melina Kanakaredes). Det. Lindsay Monroe (Anna Belknap), Det. Danny Messer (Carmine Giovinazzo), and Dr. Sheldon Hawkes (Hill Harper) investigate a dead man, Kevin Carmichael, on a train, they have double trouble after the train suddenly takes off.

Danny manages to stop the runaway. Flack notices the team is riding on Train number 3 which stopped at 33rd Street. Mac Taylor's mystery caller has struck again!

Where is Mac? Chicago, of course. He is trying to find out who has called at 3:33 a.m. ever since London ("Can You Hear Me Now") with Peyton Driscoll (Claire Forlani). The trail leads to the Chicago Tribune building, where he starts searching rooms. One has a long dead corpse in it.

Letters are painted nearby, implying a hangman's game. Those missing spell "coward". Det. Brennan of the Chicago PD takes elimination prints and DNA just to ensure Mac is not involved. She listens as he shares about his phantom caller. She tells him he will not be part of a joint investigation. When Mac later mentions 'bad reception' is in the air, Brennan takes the rebuke with grace.

Back at the lab, Chief Detective Sinclair (Mykelti Williamson, Forrest Gump) is not happy when Chicago phones, asking why NYPD personnel is on their turf. He wasn't informed, so Flack heads to O'Hare. Mac shares from his past, and it's a doozy!

When he was 14, he and his best friend, Jimmy were along for the ride as a package was delivered late at night to apartment 333. Inside was a large wad of cash, except a portion was missing. A fight broke out. Mac could have stopped things, but Jimmy had to step in when Mac froze. Two people ended up dead.

Until now, Mac and Jimmy have never told anyone what happened. What neither knew was that Jimmy's younger brother, Andy, secretly watched. Some would call this kid Andrew.

Stella knows him well. Drew Bedford (Kerr Smith Dawson's Creek), Stella's not-so-secret admirer ("The Deep") is the 333 caller! A takedown goes awry when Mac is abducted. Drew wants revenge for his brother's death that night years ago. It's not long before NYPD steps in and rescues Mac. Drew is arrested.

Whew! The caller storyline is over. Drew was not on my list of suspects. However, having him as Mac's stalker wraps up the problem of Stella and her boyfriends. There were, however, clever bits.

The reference to the cocaine bust ("Snow Day") was nice. Mac was reminded he has chinks in the armor which cannot be removed, no matter how hard he polishes. Although Drew would like to think otherwise, the real coward was Jimmy. He killed someone, and never spoke up. More than likely, he would have gotten off.

Sinclair shone! This relationship is the reverse from Lt. Dan and Bubba in Forrest Gump. Gary Sinise as the crime lab head working under Mykelti Williamson as the detective in charge of all other detectives works very well indeed. Both actors give standout performances. Sinclair may not know the whole story, but he trusts Mac enough to don a bulletproof vest himself in the effort to catch Drew. He even calls for help once Mac goes missing. Now, can someone persuade him to promote Flack?