Warning: SPOILERS for Star Trek: Picard Season 3, Episode 3 - "Seventeen Seconds"Star Trek: Deep Space Nine's finale about what happened to Odo (Rene Auberjonois), DS9's heroic Changeling. Star Trek: Picard season 3's third episode concluded with a dual reveal that the story's villains are Changelings from DS9's Dominion. But it was the B story of Worf (Michael Dorn) and Raffi Musiker (Michelle Hurd) interrogating a Changeling named Titus Rikka (Thomas Dekker) that yielded a big reveal about Odo.
Constable Odo was a Star Trek: Deep Space Nine series regular for all seven seasons. A shapeshifter who was isolated from his people, Odo became the Chief of Security of Deep Space Nine, first working for the Cardassians and then for the Bajoran Militia and Starfleet. A stern believer in justice, Odo was a deeply complicated and emotionally torn individual. Throughout the course of DS9, Odo learned he is part of the Founders of the Dominion, but he stood against his people during their effort to conquer the Alpha Quadrant. Odo also fell in love with Major Kira Nerys (Nana Visitor). When the United Federation of Planets won the Dominion War, Odo chose to return to his people to cure the Great Link of the fatal disease implanted by Section 31. Odo was canonically never seen again after DS9's series finale, "What You Leave Behind."
Picard Season 3's Odo Easter Egg Answers A Big DS9 Finale Question
With the revelation that the Changelings are the secret enemies of Star Trek: Picard season 3 comes the answer to what became of Odo after Star Trek: Deep Space Nine's finale. After Titus Rikka was exposed as a Changeling who stole experimental weapons from Daystrom Station, Worf told Raffi exactly why he is now "a contractor" for Starfleet Intelligence. Worf was ed by "a man of great honor" who informed him a rogue faction of Changelings refused to accept the Dominion's defeat and broke away to exact revenge on the Federation. The "man of great honor" Worf refers to can only be Odo, his friend from Deep Space Nine. It also makes sense Odo would connect with Worf, who rose to the rank of Starfleet Captain after DS9 ended.
It's not clear how Odo reached out to Worf about the renegade Changeling plot, but it's likely Odo has remained in the Great Link in the Gamma Quadrant since DS9 ended. When Colonel Kira was alone and watching the Wormhole to the Gamma Quadrant. Kira was obviously missing Odo as well as Captain Benjamin Sisko (Avery Brooks). It's possible Odo left the Great Link to visit the Alpha Quadrant and connect with Worf, and possibly Kira as well, at some point before Star Trek: Picard season 3. But Odo's bond with the Great Link was difficult for him to sever, even for Kira, and it's quite possible he has remained in the Omarion Nebula for the duration after DS9 ended.
Why Odo Can't Appear In Star Trek: Picard Season 3
Worf mentioning Odo (although not by name) is an exciting development for Star Trek: Deep Space Nine fans, and the Changeling threat fulfills Star Trek: Picard season 3's promise to be a sequel to both DS9 and Star Trek: Prodigy season 1. Although Rene Auberjonois has ed on, it's heartening to know Odo is still alive and well in Star Trek: Picard's era, and the heroic Changeling is still making a difference.
Star Trek: Picard Season 3 streams Thursdays on Paramount+.