Jack watches Dan eat a donut dipped in guacamole, then pop some pills for indigestion. Then Dan learns that a rookie just broke his department record for push-ups. Dan visibly strains to regain his title, until Jack - fearing for his partner's health - interrupts: They've got a burglary case to investigate.
Burglary victim Dr. Morris recounts his losses: a TV, stereo, jewelry, and an abstract oil painting that's worth a small fortune. Then Dan, complaining about the heat, suddenly collapses.
Dan comes to and refuses hospitalization but agrees to let Morris run some tests in his office. When Lt. Ruiz learns that Dan collapsed on the job, she confines him to desk duty until the test results come back.
Meanwhile, Morris is getting slapped around by Rondo Green, who now wants $20,000 to find a buyer for the painting. Morris, cash-strapped from his divorce, explains that he's yet to collect the insurance on the painting. When Green gives him a day to get the cash, Morris is met by his babe-alicious girlfriend Angie, who comforts him with kisses.
Dan immediately tries to get back on the street, but his vision blurs, and he slumps into his chair. Ruiz tells Jack to take a new partner: the ever-annoying Hodges.
Checking the test results, Morris discovers that Dan is OK, but he has a rare blood type: AB negative. Morris tells his secretary to contact the very old, very rich Bronson Jones. Meanwhile, Dan and Hodges visit fence-turned-snitch Julius and ask him to find out if anyone is trying to sell a stolen painting. Julian says that people don't generally fence expensive paintings, but he'll check.
Back at the station, Samantha teaches Dan how to use a computer and installs Foghat's "Slow Ride" as his ringtone. Dan is thrilled and gives her an autographed VHS copy of his "Savage & Stark" TV movie. Meanwhile, Jack - thinking about Julian's reaction - wonders if the painting was stolen as part of an insurance scam, and he asks Dan to enlist Asst. D.A. Liz's help.
When Dan asks Liz for a warrant to check Morris' insurance records, she refuses, citing lack of evidence. Dan - claiming he's near death, and saying that she'll never find a better man than Jack - begs her to reconsider, which she does.
Meanwhile, Morris meets with Jones and his bodyguard. Jones needs a kidney, but he can't get one because he has a rare blood type and won't stop smoking even though he's already on oxygen. When Morris says that he's found a matching donor (Dan), Jones agrees to pay him $500,000.
As Dan and Hodges have a street meeting with Jack and Samantha, Julius phones Dan with news that Rondo Green is trying to move a painting. Then Ruiz arrives and orders Dan back to the station.
Then Jack and Hodges visit Green's apartment. Green trips while attempting to escape, making it easy for Hodges to subdue him. Jack takes the stolen painting and Green back to the station, where Hodges exaggerates his heroics. Meanwhile, Green calls Morris and threatens to tell everything - unless Morris bails him out. Morris agrees, then Angie tells him it's time to make that half-million.
Angie finds Dan at Julian's bar and comes on so strong that Dan leaves with her. Liz interrupts her make-out session with Jack to relay what Dan told her and suggest he call him. Meanwhile, Angie interrupts her make-out session with Dan to stick a chloroform-soaked towel over his mouth and knock him out.
The next morning, while Jack phones Dan - who doesn't answer because he's strapped to a gurney in Morris' basement - Liz informs Jack that Morris took out three separate insurance policies on that painting. Jack wants to question Green, but he's free on bail. Jack asks Samantha to hack into the phone system and find out who Green called to bail him out.
Green, now shooting pool at Morris' house, still wants his $20,000. When Morris refuses, Green attacks and Morris K.O.'s him with a pool cue.
Morris drags Green into the basement, where Angie tells him not to worry. (Flashback to Angie cuddling up to Green, telling him about the value of the painting and if she'd known that Morris' wife would take all his money, she wouldn't have broken up the marriage.) When Green comes to, Angie quickly knocks him out again - and Samantha tells Jack that Green's jailhouse phone call went to Morris.
While Angie tries to convince Morris that they should sell all of Dan's body parts, Dan regains consciousness and walks out the door - right into Jones' just-arriving bodyguard, who knocks him down, sending Dan's cellphone flying.
Before Morris can inject Dan with a sedative, Jack's on his doorstep, returning the stolen painting. And, thanks to a call from Liz, Jack hears Dan's Foghat ringtone coming from the bushes.
Jack breaks in and exchanges gunshots with the bodyguard, felling him. Green comes to, attacks Jack, and gets K.O.'d. While Jack frees Dan - explaining his illness was a toxic reaction to those indigestion pills (they'd expired 20 years ago) - Morris and Angie escape in his car, crash into the bodyguard's vehicle, and run. With a flying leap, Dan catches them both.
Back at the station, Dan finally plays Jack's phone message of love (they exchange hugs), congratulates the new push-up champ, and invites everyone for drinks at Julius' bar - everyone, that is, except Hodges.