The one where they find Khan and his people. Khan, of course, tries to take over the Enterprise.
Necessary prequel (yes, that’s advice, both are NF streaming) for ‘Wrath Of Khan’, and pretty good just by itself – especially the scenes with Khan vs. Kirk.
Highlights:
Eugenics War references
McCoy’s informative bravery
Khan’s performance
Kirk and Khan’s grudging mutual admiration
Lowlights:
recurrent fatigue
Spockism: “Unify, Sir? Like a team of animals under one whip?”