Admiral James T. Kirk is facing a midlife crisis as he ages out of his role as a starship captain. During a routine inspection of the USS Enterprise, now a training ship, Kirk’s birthday celebration is cut short by a distress call from the space station Regula I. Meanwhile, the USS Reliant, searching for a lifeless planet to test the Genesis Device—an advanced terraforming technology—mistakenly lands on Ceti Alpha V, where they encounter Khan Noonien Singh. Khan, a genetically engineered superhuman from Earth's past and an old foe of Kirk's, seizes control of the Reliant.

Khan's wrath, fueled by the loss of his wife and the harsh conditions on Ceti Alpha V, leads him to seek revenge against Kirk. He plans to use the Genesis Device as a weapon of mass destruction. The Enterprise heads to Regula I to investigate, only to fall into Khan’s trap. A fierce battle ensues, testing Kirk’s strategic skills and the resilience of his crew. As the cat-and-mouse game between the two captains escalates, Kirk must outwit Khan to protect the Genesis Device and save his shipmates.