" I don't need therapy. It's not my fault there's a disaster every time I blink. I want to f***ing move on and leave it behind me"
Nate is the firstborn of the Fisher siblings, and arguably the one whose life was most drastically changed by his father's death. Until then, he hadn't dedicated his life to much of anything - except, perhaps, keeping far away from his family. At the age of thirty-five he was a college dropout who hadn't had a romantic relationship that lasted longer than two months and the pinnacle of whose career was Assistant Manager of Organic Produce at Seattle's "highest-volume food co-op." When he inherited half of Fisher and Sons Funeral Home, Nate's first impulse was to sell the business to his father's archrival, Kroehner Service International. But he thought better of it, convincing his brother David that Fisher and Sons should remain independent, with the two of them running it. As a result, Nate suddenly found himself totally immersed in the family business - and his family.
In addition, Nate had a stormy romantic relationship with Brenda Chenowith, a brilliant and complicated woman with family issues of her own. Nate feels deeply connected to Brenda and even planned to marry her, but a series of events pulled the two of them apart: on a trip to Seattle, Nate slept with Lisa Kimmel, an old "fuck buddy" and fathered a child, an infant daughter named Maya. Nate confessed this to Brenda, but his guilt quickly turned to anger when he discovered that Brenda had had several infidelities that she'd concealed from him. They split up and Brenda subsequently left town.
Coloring all of Nate's relationships at this time is a growing sense of his own mortality. He's diagnosed with arteriovenous malformation (AVM), a potentially life-threatening brain disorder. He tries to keep his illness secret, but his condition deteriorates, requiring highly risky surgery. Although he survives the operation and marries Lisa, Nate's life is still far from settled. He struggles to reciprocate Lisa's love for him, until the two of them come to an understanding that brings them closer - when something horrible happens. Lisa disappears on her way to visit her sister in Santa Cruz, and is later found dead.
Shocked with grief, Nate throws himself into his new role as a single father, coming to heads with Lisa's sister Barb and her husband Hoyt, who threatens to fight for custody of their niece. The tumult and trauma of coping with his own loss drives him to take a sabbatical from the funeral business, and he finds some escape in a low-stress job at a kennel. Forced to return to Fisher & Diaz in the wake of David's carjacking, Nate discovers he has some post-traumatic stress of his own to work out.
He turns to Brenda for emotional support, only to discover she's getting serious with a new guy, an even-keeled (French Horn) player named Joe. She tries to be there for Nate as a friend, though it's clear their feelings for one another are unresolved. On the brink of moving in with Joe, Brenda panics and visits Nate, and two end up having sex. She confesses her indiscretion to Joe and assures him it won't happen again, but soon finds herself drawn back to Nate. When the two are caught in a compromising embrace, Brenda's relationship with Joe is officially over.
Jumping back into things with Nate, Brenda impulsively tells him she loves him during sex. But he's unable to return the sentiment, claiming he's still adjusting to widowerhood and his guilt over Lisa - and this leads to another split. After a dream in which his father appears as a comic book incarnation of death - taking away everything he holds dear, including Brenda - Nate realizes he wants to be with her, and the two get back together once again.
Soon after a memorial service held by Lisa's family, Nate finds a Polaroid of Lisa in a book given to him by Barb's young daughter shortly after Lisa's death. The photo disturbs him, especially when he notices that Lisa's outfit is the one she wore when she died, suggesting the picture must have been taken just before she died. Suspecting she might not have been alone when she died, Nate drives to Santa Cruz, where he learns the shocking truth about Lisa's relationship with her brother-in-law -- and the circumstances surrounding her death.
Traumatized by his discovery and Hoyt's sudden suicide, Nate races back home to Brenda: "Let's get married and have a baby."