Lieutenant Commander Airiam's death during Star Trek: Discovery season 2 was a surprisingly tragic loss of a character with great potential, but fans may be surprised to learn that Airiam might not be as gone as they think. Star Trek: Discovery season 3 continues where the last season left off, with the crew propelled into the future as a way to protect the universe from Control, the rogue Section 31 AI that was attempting to wipe out all sentient life. Ultimately, Discovery's crew is able to defeat Control by the end of season 2, but this defeat comes with a number of casualties, Airiam chiefly among them.
During season 1, Airiam was mostly a background character with very little backstory, but season 2 developed her into a more fully-realized character by revealing that her distinctive appearance is due to being a cyborg, her augmentations the life-saving result of a shuttle crash that severely injured her and killed her new husband. Unfortunately, towards the end of the season, Airiam meets her own death when Control takes over her body, using her cybernetic augmentations as a way to gain access and use her for its own means. For the good of the entire universe, Airiam chooses to sacrifice herself to keep Control away from Discovery, dying when she is blown out of an airlock into space.
Despite her death, however, Star Trek: Discovery's writers have found a way to keep Airiam "alive" going into season 3, a way that involves some interesting behind-the-scenes information. Actress Sarah Mitich played Airiam during season 1, but the role was recast with actress Hannah Cheeseman in season 2. While not officially confirmed, a rumor that Mitich had an adverse reaction to Airiam's extensive makeup serves as the most likely reason for Cheeseman taking over the role. However, Mitich was not let go from the show and has since been recast as another character named Lieutenant Nilsson. Nilsson was seen in several episodes of season 2 leading up to Airiam's death, and after her death, Nilsson took over Airiam's station on the bridge and assumed her role of spore drive ops officer. This is clearly an attempt by the creative team to allow Sarah Mitich to continue to embody her original role symbolically, and for fans who recognize Mitich and know the context of her recasting, it is a surprisingly poignant way to keep Airiam around even after her death.
In addition to this, it is clear that the crew is still mourning Airiam's death in season 3. In episode 2, when asked by Phillipa Georgiou why she stayed on Discovery instead of returning to the Enterprise, the new chief of security Commander Nhan tells Georgiou that she stayed for Airiam, to honor the sacrifice she made in the line of duty. This shows that while Airiam may not be alive any longer, her memory continues to live on in the hearts and minds of those who knew her and will serve as an inspiration for her crewmates to make sure that her death was not in vain.
The Star Trek franchise has historically not been averse to killing off supporting characters if it serves the plot. Star Trek: Discovery, however, has found a way to give a supporting character not only a dignified death but also a chance at symbolic reincarnation. While Airiam's potential was cut short with her death, Luietenant Nilsson's potential is just beginning, and Sarah Mitich and the creative team have the chance to honor Airiam in their portrayal of Nilsson. In this meaningful way, Airiam can continue to remain part of Discovery's crew in season 3.