"Case Closed: The Fourteenth Target" is the second feature film in the "Case Closed" (Detective Conan) franchise. The narrative centers on a series of targeted attacks against individuals connected to Kogoro Mouri, a private detective and father of Ran Mouri. The victims are linked by their names, each containing a number from one to thirteen, corresponding to the order of their targeting. The assailant leaves behind playing cards as clues, with the numbers matching the victims' names. The pattern suggests a countdown, with the final target being Kogoro himself.

Conan Edogawa, the protagonist and a brilliant young detective trapped in a child's body, investigates the case alongside Ran and Kogoro. The investigation reveals that the crimes are tied to a past incident involving Kogoro, who once testified in a court case that led to the imprisonment of a man named Kunihiko Kudo, Conan's father. The assailant appears to be seeking revenge, using the numbered targets to draw Kogoro into a deadly game.

As the attacks escalate, Conan deduces that the perpetrator is someone with intimate knowledge of Kogoro's past and his relationships. The story builds tension as the characters are placed in increasingly perilous situations, culminating in a dramatic confrontation aboard a luxury cruise ship. The final act reveals the identity of the assailant, whose motives are rooted in personal grievances and a desire for retribution.

The film explores themes of justice, revenge, and the consequences of past actions, while maintaining the series' signature blend of mystery, deduction, and suspense. Key characters include Conan, whose sharp intellect drives the investigation; Ran, who provides emotional depth and moral support; and Kogoro, whose past mistakes become central to the unfolding mystery. The narrative is structured to keep viewers engaged through a combination of clever clues, red herrings, and a steady progression toward the climactic resolution.