Just as Star Trek: Discovery has featured several different Captains of the USS Discovery throughout its five-season run, the show has also introduced four different Number Ones. Since its beginning, Discovery has been less of an ensemble show than previous Star Trek series, and the crew of the USS Discovery has been constantly shifting. Discovery tells the story of Michael Burnham (Sonequa Martin-Green), who has gone from being an accomplished First Officer to a notorious criminal to the Captain of Discovery. Burnham has filled the position of Number One more than once, and two of her best friends have also taken on that role.
Ambassador Saru (Doug Jones) and Lt. Sylvia Tilly (Mary Wiseman) have both served as First Officers of the USS Discovery, although their careers have since taken them in different directions. In Star Trek:Discovery season 4, the show found a dynamic that worked well, with Burnham as Captain and Saru as her First Officer. But Discovery can never go too long without shaking things up, and Callum Keith Rennie’s Commander Rayner did just that when he joined the cast of Star Trek: Discovery season 5. As Captain Burnham’s newest Number One, Rayner has proven to be a great addition to Discovery’s crew, despite (and also because of) his gruff, no-nonsense command style.
During the two-part premiere of Star Trek: Discovery, Saru was serving as the Chief Science Officer on the USS Shenzhou, under the command of Captain Philippa Georgiou (Michelle Yeoh). After Commander Burnham committed mutiny and Captain Georgiou was killed, Saru was promoted Commander and became First Officer on the USS Discovery, under the command of Captain Gabriel Lorca (Jason Isaacs). Although Saru had not yet gained the confidence he would in later seasons of Star Trek: Discovery, he proved to be a capable and compassionate First Officer.
Saru commanded the USS Discovery for its journey to the 32nd century, and he was promoted to Captain. Saru later took time away from Starfleet to become a member of the village council on his homeworld of Kaminar. After the Dark Matter Anomaly destroyed Kwejian, Saru returned to Discovery as Captain Burnham’s First Officer, retaining the rank of Captain but choosing to go by the designation Mr. Saru. As the first Kelpien in Starfleet, Saru had already made history, but in Star Trek: Discovery season 5, Saru accepted a position as a Federation Ambassador, adding another achievement to his impressive resume.
When Star Trek: Discovery began, Commander Burnham was serving as the First Officer on the USS Shenzhou, under the command of Captain Georgiou. After her subsequent mutiny, Burnham served six months in prison before transferring to the USS Discovery, where Captain Lorca assigned her as a Specialist in the science division. After Michael helped end the Federation/Klingon War, she was fully reinstated as a Commander and became Chief Science Officer on Discovery. At the end of Star Trek: Discovery season 2, Burnham wore the Red Angel suit to lead the USS Discovery into the 32nd century.
Captain Burnham arrived in the future a year before Discovery, but she later reconnected with her former crew and reluctantly accepted the role of Captain Saru’s Number One. Michael served as First Officer throughout Star Trek: Discovery season 3, until she helped take the ship back from Osyraa (Janet Kidder), the leader of the Emerald Chain. Saru then suggested that Burnham take over as Captain, and Admiral Charles Vance (Oded Fehr) assigned Michael as Captain of the USS Discovery. Michael Burnham was a fine First Officer (aside from the whole mutiny thing), but she truly excels at being a Starfleet Captain.
Sylvia Tilly began her Star Trek: Discovery career as a cadet aboard the USS Discovery under the command of Captain Lorca. After the end of the Klingons’ War with the Federation, Tilly was promoted to Ensign and was placed on the command track. She continued on this trajectory until Discovery traveled into the future. When Captain Saru demoted Burnham for insubordination, he asked Tilly to be his First Officer. Although she was initially reluctant to take the job, fearing others on the ship were better qualified, Tilly’s fellow crew members assured her she was the right choice as Number One.
After Commander Burnham helped take the USS Discovery back from Osyraa and became Captain, Tilly remained First Officer and was promoted to Lt. junior grade. Tilly then began to question whether she wanted to remain on the command track, and spoke with Dr. Hugh Culber (Wilson Cruz) about ways she could step out of her comfort zone. Culber recommended Tilly for a mission that involved leading a group of young Starfleet cadets. Although the mission quickly turned dangerous, Tilly successfully coached the cadets through it, and she later accepted a teaching position at the recently reopened Starfleet Academy.
Callum Keith Rennie’s Commander Rayner joined the cast of Star Trek: Discovery for its fifth and final season, and the gruff former Captain has proven to be a breath of fresh air. In Discovery’s season 5 premiere, Rayner held the rank of Captain and commanded the USS Antares, but was asked to accept early retirement after making a questionable call during a Red Directive mission. Captain Burnham, however, asked Rayner to be her new First Officer after Saru accepted a position as a Federation Ambassador.
As a Kellerun, Commander Rayner’s personality contrasts sharply with the more optimistic crew of the USS Discovery, and his command style is very different from Burnham’s. Rayner has struggled to relate to Discovery’s crew members and adapt to Michael’s command style, but his advice and knowledge have helped save the day on multiple occasions. As Discovery races against couriers Moll (Eve Harlow) and L’ak (Elias Toufexis) to find the Progenitors’ treasure, Commander Rayner has proven invaluable to the mission and remains a highlight of Star Trek: Discovery season 5.
New episodes of Star Trek: Discovery stream Thursdays on Paramount+.
