Inspector Zenigata attends a politician's birthday party following a forged Lupin calling card. Amid the resulting chaos, he chases Lupin III across the mansion grounds and traps him, only to be shot in the chest by an assailant using a distinctive silver Walther P38 pistol. The critical injury plunges him into a coma where he flatlines briefly. Remarkably, Zenigata revives upon hearing his ICPO superior mention Lupin's name, demanding the thief's location before collapsing unconscious again.

After regaining consciousness, Zenigata ignores direct ICPO orders to drop the case. He forces an investigation by leaking information about the assassins' organization, Tarantula, to the media, declaring his commitment to stopping evil regardless of government constraints. Recovering in the hospital, he receives a fruit basket from Lupin, prompting a furious escape attempt through the window. This encounter reveals Tarantula's island location via a hidden note in the basket, reigniting Zenigata's resolve.

His actions throughout underscore his unwavering focus on capturing Lupin, intertwined with a deeper sense of justice that overrides bureaucratic limits. Despite physical vulnerability, his determination remains steadfast, culminating in his arrival on the assassins' island with police reinforcements during the climax.