While hot on the trail of a serial killer in New York City in 2008, Detective Sam Tyler gets hit by a car. But that's just the beginning of his troubles. When he wakes up, he's in 1973. He's not sure how, but the one thing he does know is that his future is inexplicably linked with his past.
En route to an arrest, Sam Tyler and Maya Daniels argue over the state of their relationship and whether Sam meant it when he said, "I think it's time to propose." When they meet with Captain Bellow and are about to bust into suspect Colin Raimes's apartment, Raimes, just returning from getting groceries, sees them and runs. Sam chases Raimes through a park and fights with him. After a scuffle, Sam arrests Raimes for the abduction and murder of Laurie Stewart.
Sam still dreams of Maya, but wakes up to his new "reality" of 197 in an apartment with a communal bathroom and a run-in with a naked hippie named Windy.
Sam, Chris and Ray walk through a park to get to a crime scene. Sam vividly remembers playing in that very park as a 3 year-old. The detectives push their way through a throng of hippies gathered to see The Maharishi, a man who chants philosophical gibberish from a tent with three diamonds embroidered on the side. Ray rants about his hatred for hippies as the men arrive at their destination, a murder crime scene. The dead man's personal effects reveal he is Robert Reeves, Jr., 31, and a Navy veteran.
We open on Sam dreaming of his mother singing the Sandman song to him as a 3 year-old in 1973. Sam has fallen asleep in his apartment chair and wakes up confused about his time warp. He takes a walk in the neighborhood, and passes a little black girl who sings the Sandman song. He realizes it's the same girl whose picture he found in the shoebox in the previous episode: yet another bizarre coincidence in his new reality. As she bikes away, he witnesses a gangster, Nick Profaci, trying to force a woman into his Cadillac. Profaci tells Sam to hit the bricks, but Sam takes him down and arrests him. As he does, he looks up at the woman -- only to realize it's his mother, Rose Tyler!
Over the radio, the words of disc jockey Brother Lovebutter fill the air, mourning the death of a young soul. Lt. Hunt and Sam arrive at a crime scene where a 9 year-old black girl, Keisha Davies, has fallen to her death from a six-story apartment building. Sizeable Ted tries to control the mostly African-American crowd gathering. Annie and Ray are also on the scene. Sam is startled to see that this was the girl whose picture he found and whom he had seen riding a bike in previous episodes.
For Ray's birthday, the 125 shuts down and holds a rowdy party: heavy drinking, dancing with hookers, etc. The next morning, Sam wakes up hung-over at the precinct to answer a phone call... from his mother in 2008. She tells him unless he gives her a sign, she will turn off his life support at 2 pm. Sam screams for her not to, but she can't hear him. Lieutenant Hunt walks into the squad room, waking up his bleary-eyed detectives and informing them there's a hostage situation at Memorial Hospital.
Sam dreams of a childhood memory when his father tried to give him a new toy spaceship for his 4th birthday, but he rejected it, unwilling to give up his old one.
A longstanding competition between Lt. Hunt and the detectives of the 1-2-5 and Lt. Anthony Nunzio and his men of the 1-4-4 heats up when the Russian mafia appears to be linked to a bank robbery. The investigation becomes a furious contest of one-upmanship between the two squads. A nine-year-old boy at the crime scene possibly holds the key to cracking the international case, which has Hunt, Sam, Ray and Chris looking over their shoulders not only for possible suspects, but for rival detectives as well. Meanwhile a young, attractive social worker involved catches Sam's eye and he his hooked.
Sam Tyler receives a mysterious phone call that leads to a headless body. Simultaneously Lt. Hunt finds a severed head delivered in a gift box to the precinct, which sets off the discovery of a chain of bizarre decapitations. Meanwhile, Ray's ne'er-do-well brother, Eddie, may be entangled with the murders, but the peculiar situation leads the 1-2-5 to a biker, a Wall Street bigwig and a terribly disfigured man. As Sam, Hunt and the rest of the detectives sort out these hideous crimes, Ray makes a life-changing decision, and Sam makes an extraordinary discovery about the original tipster phone call.
Death threats targeting rock sensation Sebastian Grace expose Sam and Chris to the anything-goes rock and roll lifestyle, including Grace's groupie, "Rocket Girl," and an FBI agent known as "The Sorcerer." But is this over-the-top world also out of this world? It certainly seems so after Chris finds Sebastian and "Rocket Girl" watching and waiting for UFOs in a desolate area of New Jersey known as the Meadowlands. The otherworldly mystery builds as the groupie disappears, and Sam believes he may finally have found a way back from the 1970s to 2009.
After New York City Councilman Bobby Prince is unexpectedly caught with a hooker during a police raid on a motel, he shares a stunning secret with Detective Sam Tyler. The mysterious Councilman's haunting words shatter Sam's world, leaving him with more questions than answers. Meanwhile, a chaotic shooting at the 1-2-5 causes Lieutenant Hunt to call a lockdown at the precinct house. Adding to the electric atmosphere, family tensions explode as Hunt and his daughter, Maria, confront each other. And change is definitely in the air when Ray introduces Annie to his wife, Denise.
Joey Conway, a big-name newspaper columnist, turns up dead in 1973 and Detective Sam Tyler is certain he knows the killer. It just happens to be someone he remembers from another murder case 35 years in the future. Spurred on by powerful flashbacks from 2008, Sam's behavior seems increasingly erratic to Lieutenant Hunt, Ray, Annie and Chris, who have another suspect in mind. When Sam goes totally out on a limb and faces surprising consequences at the 1-2-5, it looks like the once-and-future killer may get away with the crime.
When student radicals from the Weather Underground target the police with bomb threats on the anniversary of the death of their charismatic leader, Rodney Slaven, it becomes all too personal to Lt. Hunt, who loses several close friends in the incendiary aftermath. As the investigation heats up, Sam Tyler, Annie and Hunt uncover mysterious connections to one of the students and a political science professor, Pat Olsen. The bomb threats continue as Hunt, suspiciously secretive, attempts to discover Olsen's possible connection to Slaven. With the 1-2-5 walking a dangerous tightrope to discover the target of the next bomb, the case takes a totally unforeseen but deadly turn.
When Valerie Palmer, a Pan Atlantic air hostess turns up dead, Annie volunteers for a dangerous undercover mission, posing as the murdered woman to help solve the second in a possible series of brutal homicides. Annie, Sam and Ray, working one of Valerie's flights covertly, uncover an unlikely suspect. Then, an invitation to a lurid swingers' party leads to an evening full of sensational surprises -- not just for Annie and Sam, attending undercover as a couple, but Lieutenant Hunt also arrives with a special guest to mix it up. Juicy sexual escapades bring the swingers' party to a fever pitch, but will the murderer be revealed? Finally, Annie confronts Hunt with the courage of her convictions about her future at the 1-2-5.
When Detective Sam Tyler poses as a streetwise tough to infiltrate a vicious New York City gang suspected of truck hijackings, he's pushed to the limit not to blow his cover, and he reveals a much darker side. A bare-knuckled fist fight with a gang member, a late-night deal to buy a truckload of stolen VCRs, and even time behind bars at his own 125th Precinct are all necessary elements of Sam's scam. But can he keep up the ruse when he's told to shoot a bound-and-gagged woman? And his attraction to the gang leader's sister also seems to be part of a recipe for disaster.
Crime fighting gets extremely personal at the 125th Precinct after Ray and Chris are shot by the leader of a vicious New York City gang of truck hijackers. When the shooter is then murdered outside a neighborhood bar, fingers on both sides of the law point to Sam, who has been posing undercover as a streetwise tough guy to bust the gang. With the evidence stacking up against him, a perplexed Sam questions his own innocence and must rely upon his friends at the precinct to bend the rules as he tenaciously searches for the real killer.
Sam Tyler's past, present and future all confront him when he receives a phone call with instructions on how he can return to 2008: All he needs to do is complete three tasks. But a dizzying set of circumstances inside and out of the 1-2-5 makes him think twice. When love, death, promise, hope, fear and mystery converge, will Sam decide to stay in 1973 or return to the future?