Spock

Spock serves on the Enterprise as a lieutenant under Captain Christopher Pike. Since childhood he's had visions of a figure called the Red Angel. He checks himself into a psychiatric facility, escapes and is accused of killing three doctors. Michael Burnham, the adoptive sister who pushed him away when they were kids, goes looking for him.

Hunted by Section 31 and an AI called Control, Spock goes with Burnham to Talos IV, where the Talosians heal him. He joins the Discovery and helps figure out who the Red Angel is. In the end, the Discovery jumps 930 years into the future, and Spock recommends that Starfleet never mention the ship or its crew again.

Back on Pike's Enterprise, now as science officer, Spock tries to balance his Vulcan and human sides. He's engaged to the Vulcan T'Pring and works at keeping the long-distance relationship going. During a mind-meld ritual, the two accidentally swap bodies and have to pass as each other.

He also grows close to Nurse Christine Chapel, and his friendship with Pike deepens. At the end of the season, a glimpse of another future shows how tied together their fates are.

With James T. Kirk in command, Spock becomes first officer and the captain's closest friend, always trading barbs with Dr. McCoy. In "The Menagerie," he mutinies and takes the Enterprise to bring his badly injured former captain, Pike, to Talos IV.

In "Amok Time," he goes through pon farr, the Vulcan mating cycle, and returns to Vulcan to marry T'Pring. She picks Kirk as her champion, and Spock has to fight the captain in ritual combat. Spock thinks he's killed the captain, and when he sees him alive, he lets slip a smile.

Spock is a captain and Academy instructor, but hands command to Kirk when Khan attacks. In the Mutara Nebula, the Enterprise can't outrun the Genesis blast. Spock knocks out McCoy with a neck pinch, mind-melds with him saying "remember," and walks into the irradiated engine room to fix the ship. He dies saying goodbye to Kirk. His casket lands on the new Genesis planet.

His body is reborn on the planet, and his katra, kept inside McCoy, is restored to him in a ritual on Vulcan. Spock slowly relearns who he is and helps the crew travel to 1986 Earth to bring back humpback whales.

Spock meets Sybok, his half-brother, and later drives peace talks with the Klingons after the explosion of Praxis. When Chancellor Gorkon is assassinated, he takes over the Enterprise, finds out his protégée Valeris is a traitor and breaks up the conspiracy in time for the Khitomer conference.

Decades later, now an ambassador, he turns up on Romulus, and Starfleet fears he's defected. Picard and Data go after him and find that Spock is secretly working to reunify Vulcans and Romulans. Picard tells him Sarek has died and, through a mind meld, Spock feels the father Picard carries. He decides to stay on Romulus.

In 2387, a supernova threatens Romulus. Spock tries to stop it with red matter, but he's too late and the planet is destroyed. His ship and that of the Romulan Nero fall into a black hole and land in the past, 25 years apart. Nero attacks the ship Kelvin and creates a new timeline.

Nero strands Spock on the icy planet Delta Vega so he can watch Vulcan be destroyed. There, Spock meets the young Kirk of this reality and helps him take the Enterprise. After the victory, he talks with his younger self and decides to help the surviving Vulcans found a new colony.

Spock was the only character from the rejected pilot "The Cage" to stay on the show. Leonard Nimoy played him from 1966 to 2013 and came up with the Vulcan salute while filming "Amok Time," based on a Jewish blessing gesture he saw as a child. In the Kelvin timeline, Spock is Zachary Quinto. In Discovery and Strange New Worlds, he's Ethan Peck.