D.O.A.

Dex assists his friend Hal Petersham with his debut novel. They celebrate with Scotch, and Hal notices Dex gave an 'A' to a manuscript by Nick Lang and becomes furious when Dex admits he never read it.

While Dex is in his office, Nick Lang exits the campus building in what appears to be suicide. The incident unsettles Dex and complicates the upcoming celebration of Nick's work. Dex begins to sense that something darker may be at play.

Dex seeks solace in the local bars after Nick's death, trying to bury his growing sense of unease. There he encounters his admiring student Sydney Fuller, who becomes drawn to him. The chance encounter sets up a complicated relationship to come.

The next morning, Dex calls his estranged wife Gail, who reveals she had an affair with Nick Lang. She insists it was a one-off and that she didn’t discover Nick was Dex’s student until later. The revelation deepens Dex's personal turmoil and suspicions.

Dex visits the campus medical clinic, where doctors run tests and reveal that he has been poisoned. He is told he has only 24-48 hours to live, turning his personal crisis into a race against time. The clock begins to force a new perspective on his life.

Armed with the grim news from the clinic, Dex goes to Gail's house and witnesses an obscured figure murder her. He then faints from the sedative the clinic administered, leaving him reeling and vulnerable. The murder accelerates Dex's decision to act.

Police discover scuff marks on the rooftop that suggest Nick was pushed to his death, and Dex is arrested on suspicion of murdering Gail and Nick. He makes a daring escape, plunging him deeper into a perilous chase for the truth. The case becomes increasingly personal and dangerous.

On the run and desperate for help, Dex grabs Sydney by super-gluing himself to her arm to force her cooperation. Together they attempt to piece together who might murder him and why. The uneasy alliance marks a turning point in the investigation.

As they dig deeper, Dex uncovers a web of connections around Nick Lang's death. Nick's father was a burglar; the Fitzwaring widow funded Nick's tuition, and Cookie hints at disapproval from Fitzwaring. Dex confronts the possibility that the family is involved in more than a simple tragedy.

Dex presses Cookie and Bernard with his suspicions about Fitzwaring. A tense confrontation exposes secrets and raises the stakes, as Dex becomes a direct threat to those who would keep Nick's death a secret. The tension promises a violent resolution.

Bernard knocks Dex out and drives him to the tar pits for disposal, a grim attempt to silence him. Cookie intervenes, but the scuffle escalates into chaos, resulting in the deaths of Cookie and Bernard. The tar pits scene marks the fall of two key suspects.

Imminent death forces Dex to reevaluate his cautious life philosophy. He reconnects with Sydney on a personal level, sleeping with her, and leaves a goodbye note as he prepares for the consequences of his discoveries. The moment signals a new, risk-taking chapter.

Dex confronts Mrs. Fitzwaring, who reveals that Nick Lang was her son and explains the motive behind the killings. The confession clarifies the tangled web of blackmail and control, and Fitzwaring then takes her own life to protect her other child.

Back at his office, Dex notices a green sediment in the Scotch Hal had with him. Hal ultimately confesses to poisoning Dex to steal Nick Lang's manuscript, and to murdering Gail when she caught him. Dex retrieves a gun from Bernard, and in a scuffle, he shoots Hal dead. The truth finally closes in on the motive and the killer.

Having laid out the events and the motives, Dex finishes his statement at the police station. He walks out into the world beyond the station, his life now forever altered by the revelations and the choices he made. The final image is of a man who chose to live rather than merely exist.