On the way to meet an informant, Nash tells Joe that Caitlin has planned a vacation to Jamaica. At an abandoned warehouse, a paranoid Arnold Keller reveals to Nash and Joe that his twin brother Gordon Keller, the City Administrator, has stolen five million dollars from the City Pension Fund.
Nash and Joe go to Gordon Keller's house, but Rick Bettina has beaten them there. Rick is running for City Supervisor, and is looking for a high profile case. Rick turns on gas to force Gordon out of the house, but the house blows up in a fireball.
The dead body found in the house is not Gordon Keller, but his partner Scott Mueller. They have stolen 5.5 million dollars from the City Pension Fund. Gordon Keller has a secretary/girlfriend, Carol Bodet. Joe and Evan go to Carol's apartment, but instead find Rick Bettina there. As a result of the explosion, Rick Bettina has been forced out of the SF police department. Rick is out for the reward money of $100,000.
Nash and Caitlin have missed their flight to Jamaica. Nick doesn't want to go to Joe's house while they're away. Nash and Caitlin quarrel, and she ends up throwing Nash's Willie Mays baseball out the window. The ball is lost, as they continue their argument into the office the next day.
Gordon and Carol are planning a traveler's check scheme to launder the stolen money. They buy traveler's checks, destroy them, and reclaim the amount later in a foreign country. Gordon burglarizes Arnold's home and steals his passport. Rick Bettina is outside, but mistakes Gordon for Arnold, and lets Gordon get away.
A frightened Arnold comes to the SIU, but again Rick Bettina mistakes Arnold for Gordon and tackles him. At Arnold's home, Nash deduces that torn pages under the heading "BANKS" from a telephone book indicate that Gordon and Carol are trying to launder the stolen money. Meanwhile Gordon, using Arnold's passport, attempts to purchase plane tickets to Brazil, but he is recognized. Gordon is forced to murder the ticket seller. Carol is caught by Harvey and Evan attempting to cash traveler's checks.
Caitlin has made up with Nash, but still feels badly. She enlists Joe's help in trying to locate the ball. They recreate the trajectory of the ball which leads Joe on a wild chase after the wrong ball. Caitlin distributes flyers offering a reward for the ball. She mistakenly believes she sees the ball in a dumpster, which she falls into attempting to retrieve the ball.
Under interrogation, Carol reveals the location of Gordon Keller. But listening outside via electronic surveillance is Rick Bettina. Rick beats Nash and the SIU to the location and steals the two million dollars Gordon has successfully laundered. Rick is in disguise and taunts Nash via phone as he drives away.
Meanwhile, Harvey's new girlfriend Robin takes care of his son Jerry. But mother Anna objects to Robin and, so Anna takes back custody of Jerry. Nash has finally forgiven Caitlin by giving her a new set of tickets to Jamaica. Arriving to their flight on-time (Nash has lied to Caitlin by one hour), they encounter Rick on the plane.
For more, see commentary for Episode 84