Sammy Backlin calls Spenser for protection when he's being hunted by a 'vicious horde of bloodthirsty assassins'.

Spenser kills a would-be thief in the course of thwarting a robbery. He and Susan take in the man's two children while investigating his past. Susan discovers she's pregnant.

A deaf woman hires Spenser to find a man she had been corresponding with who had gone missing. As Spenser investigates, he realizes that the missing man is somehow involved with a gang of thieves who are trying to kill Spenser in revenge for busting up their diamond heist.

One of Spenser's old trainers lures Spenser to a deserted warehouse where Spenser is supposed to be killed, to get out from under a gambling debt. Spenser survives, then turns around and protects his trainer from the goons now after him.

Spenser is hired to protect a woman's identical twin sister from assassins, only to discover his employer suffers from a split personality.

Spenser and Hawk blame themselves for failing to protect their respective clients from the clutches of the underworld, and vow to settle the score with a big-time racketeer and his henchmen.

A girl who apparently has the unique ability to 'see' through both space and time, enlists Spenser's help to solve a rash of arsons.

Spenser's been hired by a conductor to find his daughter who ran away with her boyfriend. When he finds them, she tells him that her father has been molesting her. Spenser then tells her father what she said which he denies. After Spenser leaves, he calls Hawk, who once did a job for him, to do something for him.

Spenser searches for the father of an undocumented boy killed by an unhinged unemployed man. The trail leads Spenser into a conspiracy involving the exploitation of undocumented workers on the waterfront.

A girl comes to Boston looking for her estranged father. Spenser decides to help her.

Spenser's apartment burns down, but he's allowed to move into an old fire station as thanks for saving a firefighter's life. Meanwhile, Spenser and Hawk are hired to protect the life of grand jury witness. When it starts to look like someone on the inside might be trying to have the witness killed, and that the witness may not be who she says she is, things get convoluted.

Spenser investigates the apparent suicide of a young nun, and stumbles onto a corrupt landlord.

A young criminal's father attacks a bus transporting convicts to the state prison.

With the help of Hawk, a disgusted Spenser is determined to get rid of thugs who are terrorizing his Boston neighborhood.

A wealthy man is murdererd and, surprise, an innocent man is arrested. If you've seen one Spenser, you've seen them all.

Spenser investigates the apparent suicide of a philandering financier about to turn state's evidence to bring down insider trading. Rita has problems of her own when an old boyfriend shows up. Belson hires Spenser to find his missing wallet containing a winning lottery ticket.

Hawk and Susan along with other people are held captive in a post office. Richard Brooks later seen on Law and Order during Season's 1 & 2 plays one of the hostage takers.

Marital infidelity and suspected involvement in a gambling ring lead to Lt. Quirk's suspension. Belson is shot during a raid. Spenser works to clear Quirk's name and catch Belson's would-be killer.

A young ex-con named Louis Harper steals from his boss, John Brady. Brady hires Spenser to prove it and Harper hires Hawk to protect him from leg-breakers. Spenser and Hawk team up to solve Louis' murder.

Spenser is going skiing with Susan, but when he picks her up at Smithfield High School where she works, he finds out one of her students died of a heroin overdose. Spenser gets hired by the superintendent and goes undercover as a teacher at her school to find out where the drugs are coming from. He obviously gets into it with the dealers.

Spenser becomes embroiled in the seamy Vietnamese organized crime racket after a Vietnamese crime boss uses Spenser to track down a former soldier.

NRA poster-boy Sammy Backlin breezes into town for a book signing, unwittingly involving Spenser in a shoot out. Spenser agrees to protect Sammy from gangland thugs.

Spenser runs into an old friend while visiting a recreation of a Puritan village. Spenser does everything in his power to exonerate said friend when he's accused of a brutal slaying. As he uncovers more and more, Spenser begins to think it might be hard to clear the name of a guilty man.

When Frank's niece dies of a drug overdose, Spenser and Frank go after the men responsible.

The wife of a kidnapped oil tycoon hires Spenser to deliver $1 million in ransom money to a ring of terrorists while police have the drop-off area surrounded.