Warning: SPOILERS for Star Trek: Picard Season 2, Episode 9 - "Hide & Seek"
At the end of rebuild the Borg into a new and better Collective. But before they took La Sirena and left Earth, the Borg Queen left a riddle for Jean-Luc Picard (Patrick Stewart): "To succeed, there must be two Renées - one who lives and another who dies."
Renée Picard is the most pivotal person in Star Trek: Picard's 21st-century history. Renée, the great-great-great-aunt of Jean-Luc, is the pilot of the Europa Mission, which is a landmark space flight and exploration of the solar system. Renée is destined to discover a microorganism on Jupiter's moon, Io, that is vitally important. Indeed, Renée is the lynchpin of Star Trek's entire timeline because eliminating her directly changes the course of the future and eventually leads to the rise of the Confederation of Earth. This is the reason Renée is targeted by Q (John de Lancie), who has somehow lost his powers in the past and recruited Dr. Adam Soong (Brent Spiner) to take out Renée. Soong also has a personal reason to ensure the younger Picard doesn't decide the future since wiping Renée from history means Adam becomes the pivotal figure who "saves the world" and ensures the rise of the Confederation.
So, what does the Borg Queen's riddle about Renée Picard mean? The Queen warned that the Europa Mission "must not be postponed." The obvious interpretation is that someone has to impersonate Renée and become Q and Adam Soong's target. Further, Q may have to succeed and "kill Renée," but not the real Renée. The real Renée has to complete the Europa Mission to set Star Trek's history back on the proper course so the Prime timeline can happen as it should. Logically, Tallinn (Orla Brady) is the most likely candidate of Picard's crew to die in Renée's place. After all, Tallinn is Renée's Watcher and her entire purpose is to keep the young Picard safe. This could be how Tallinn fulfills her ultimate mission to protect Renée, and it has the added benefit of none of Star Trek: Picard's series regulars dying in the past.
As Jean-Luc and his motley crew fought Adam Soong and a Borg invasion at Chateau Picard in La Barre, , Renée is safely in quarantine in Los Angeles, preparing for the launch of the Europa Mission. The Borg Queen's original plan was to steal La Sirena and shoot down Renée's starship, the Shango, from orbit. However, Renée is now safe from the Borg Queen, at least, although Q and Adam Soong are still left to be reckoned with. But not allowing Renée to pilot the Europa Mission is not an option, as the Borg Queen warned. The Europa Mission has to happen as history records because it's an absolute point in history.
Further, it likely has to be the real Renée who flies the Europa Mission and not one of Picard's crew in order to preserve history. This is similar to how Zephram Cochrane had to pilot the Phoenix's first warp flight in Star Trek: First . Although, Picard or some of his crew could Renée in the Shango just as Commander Will Riker (Jonathan Frakes) and Commander Geordi La Forge (LeVar Burton) served as Cochrane's crew in the Phoenix's cockpit, which resulted in First with the Vulcans. It's possible that Q and Adam Soong have to be led to believe that they killed Renée as the Europa Mission is otherwise successfully launched in order to set history right. The question is who will die in Renée Picard's place in the season 2 finale so that Star Trek: Picard's future can be fixed?
Star Trek: Picard Season 2 streams Thursdays on Paramount+.