A sniper puts a round into his hunting rifle and searches for a target. He fires his silenced rifle into the back of a sign painter; the painter falls dead. Nash and company arrive to find the body, but the sniper is not through yet. The sniper kills a security guard as Nash and Joe duck for cover.
Two shell casings at the crime scene indicate a .460 Weatherby hunting rifle for big game. Dead are Jorge Garcia, sign repairman and Paul Little, security guard. Fingerprints off the shell casings are not on file. Caitlin (now staying at the Hall of Justice) shows up for work with a cold. Evan informs Nash he is going to ask Cassidy to marry him. Evan proposes to Cassidy at her dorm room; Cassidy needs time to consider Evan's proposal. Evan is leaving for Chicago to visit his pregnant sister about to deliver her child; Evan hopes for Cassidy's answer when he returns.
There is another killing. Evan and Harvey almost intercept the sniper (actually two young men) as they flee the Coit Tower. They leave behind a .460 Weatherby rifle with silencer and snag a piece of bloodstained cloth on a fence. The rifle traces to a William B. Wheaton, who claims he sold the rifle at a gun show. Wheaton has two young teenage sons. Wheaton refuses further cooperation and throws Evan and Harvey out of his house.
Joe has been experiencing rats in the attic above his bedroom. Wife Inger gives Joe grief, forcing Joe to call landlord Nash at 3AM to complain. A rat exterminator fails to get all the rats. Joe goes up into the attic to nail the rat with his tennis racket; Joe misses and falls through the ceiling. Nash refuses to pay for the gaping hole. Nash and Joe agree to use an arbitrator (Joe's nephew Latio) to settle their dispute; Latio tells them to split the costs.
Nash gives Caitlin "Bridges' Brew," his grandmother's secret recipe for her cold. Caitlin accidentally breaks Nash's favorite mug - she is frantic. Nash finds the broken pieces, and using his magic scarf, puts the mug back together before an astonished Caitlin. With Joe smiling, Nash has a dozen of the mugs in his desk.
Angela is driving Cassidy's white Volkswagen beetle while Cassidy studies
for her exam. Distracted, Angela misses a stop sign. A truck broadsides the
small car, pinning it against a bulldozer. Nash is at the hospital, as is
Susan Martin, Angela's mother. They wait anxiously as the two girls are
operated on. Nash tells Joe to contact Nick and Stacy, who are staying at
his Uncle Mike's in Farmington, Missouri. Nash meets and forgives the truck
driver. Nash is informed by Dr. Wilcott that Cassidy has been killed, but
Angela has survived. Joe is there to console a broken, grieving Nash, as is
Caitlin from afar.
With Evan gone to Chicago, Harvey is hot on the trail of the two boys. Blood samples indicate a rare blood disease. Harvey gets a warrant based upon the fact that relatives of the boys suffer from the same rare disease, indicating a connection to the bloodstained cloth. Harvey arrests the two Wheaton boys from their home, much to the distress of father Wheaton.
A mistake in identity has been made - Dr. Wilcott informs Nash that it is Cassidy that has survived; it is Angela who has died. Nash goes to the bedside of an injured Cassidy with a removed spleen and several broken ribs. Cassidy awakes to a grateful Nash.
For more, see commentary for Episode 69