D.O.A.

Dex helps his friend Hal with his first book, and they celebrate with Scotch. Hal notices Dex gave an 'A' to a manuscript by Nick Lang and grows furious when Dex says he never read it. The exchange foreshadows the envy and risk that will push the plot forward.

While Dex is in his office, Nick Lang drops off a manuscript and then falls from a building in what appears to be a suicide. Dex is not implicated by that act, but the event triggers a chain of suspicions about motive and authorship. The campus atmosphere grows tense as the first death complicates Dex's life.

That night Dex goes to local bars to drown his worries. He encounters Sydney Fuller, a student who admires him, and the encounter tips the night into dangerous territory. The mix of desperation and temptation foreshadows the danger to come.

The next morning Dex calls Gail. She confirms the affair with Nick Lang and says it was a one-off, adding that she did not reveal Dex's student status at first. The revelation unsettles Dex and deepens his distrust of the people around him.

Dex goes to the campus medical clinic, where doctors run tests and reveal he has been poisoned. He learns he has only 24-48 hours to live, a prognosis that jolts him into action. The knowledge forces him to reassess who would profit from his death.

That night, Dex goes to Gail's house and witnesses an obscured figure murder Gail. He faints from the sedative the clinic staff gave him, losing track of the killer for the moment. The murder confirms his worst fears and deepens the sense that someone is closing in on him.

Police arrest Dex on suspicion of murdering Gail and Nick, but he escapes custody before they can hold him for long. He becomes a fugitive, hunted by the very people he fears.

To force help from someone he can trust, Dex glues himself to Sydney's arm and drags her along to help him deduce who killed him. They move through the city as they chase clues. Sydney reluctantly becomes his partner in a dangerous investigation.

Investigation narrows to Nick Lang's circle: Nick's father was a burglar who killed Mr. Fitzwaring, and Fitzwaring's widow funds Nick's tuition. Sydney helps piece together tangled motives and alibis as they press deeper into the case.

Dex confronts Bernard and Cookie with his suspicions; Bernard knocks him out and drives him toward the tar pits to dispose of him. Cookie intervenes, but the confrontation ends with both Bernard and Cookie dead.

The near-death experience prompts Dex to rethink his life; he reconnects with Sydney, has sex with her, and writes a goodbye note to leave behind. The act marks a turning point as he embraces a more vulnerable, alive existence.

Dex confronts Mrs. Fitzwaring, who reveals that Nick Lang is her son and explains her motive to protect the family from scandal. She admits to shooting Nick's father and Mr. Lang to silence them and then commits suicide after the confession.

Back at his office, Dex discovers green sediment in the Scotch Hal poured. Hal confesses to poisoning Dex and to murdering Gail when she confronted him. He also reveals he plagiarized Nick Lang's manuscript; Dex retrieves a gun from Bernard and shoots Hal.