Of the first three Trek films, #2 comes closest to the spirit of the TV series. It's conceived as a sequel to the "Space Seed" episode from the 1967 show, in which Kirk had banished the evil Khan (Ricardo Montalban) to the edge of the universe. Now Khan is back and looking for revenge,
via a device capable of reversing creation. This is one of the most popular in the series, thanks to a high action quotient (including a tensely staged space battle), a suitably campy turn by Montalban, and the shock value of Spock's "death." There is some novelty value, too, in the focus on
Kirk's family life back on Earth.