Quick recap
In 2285, the starship Reliant is searching for a lifeless planet to test Project Genesis, built by scientist Carol Marcus and her son David. Chekov and Captain Terrell end up on Ceti Alpha V, where Kirk exiled Khan fifteen years earlier. Khan seizes the Reliant, steals Genesis and wants revenge on Kirk. Kirk, now an admiral, takes back the Enterprise and learns David is his son. The final battle happens in the Mutara Nebula. Beaten, Khan sets off Genesis, and the Enterprise only gets away because Spock walks into the radiation-flooded engine room and fixes the warp drive. Spock dies in front of Kirk. His casket lands on the planet Genesis has just created.

