The following contains spoilers for Superman & Lois Season 3, Episode 13, "What Kills You Only Makes You Stronger," which debuted Tuesday, June 27 on The CW.
Superman & Lois Season 3 comes to an end with Lex Luthor making good on his promise for revenge against Superman and the Kent family. His vendetta comes at a particularly inconvenient time for Smallville, as everyone takes the time to move on from their respective hang-ups. And as promised by the CW series’ creative team, Season 3 ends on an epic cliffhanger as Superman finds himself fighting for his life -- and much more than that.
It’s been over a month since Luthor was released from prison and threatened Lois Lane for putting him in jail under false pretenses, with the supervillain having gone completely off the grid since. General Sam Lane advises Clark Kent to consider easing his punishment of Jordan Kent for publicly showboating as a superhero. Elsewhere, Kyle Cushing discovers Chrissy Beppo is pregnant with their child, and John Henry Irons officially asks Kyle's ex-wife Lana Lang on a date after returning to Smallville.
Kyle informs Lana about Chrissy’s pregnancy -- receiving her blessing -- while the Kent family decides to take a vacation in Italy for the summer. Sam offers John Henry a job developing new technology for the Department of Defense, along with an opportunity for his daughter Natalie Irons to enroll in the Department of Defense's academy; however, this would require them to relocate to Metropolis. But all these plans are put on hold when Superman detects Judge Reagan was murdered, and Lois immediately deduces that the killing was carried out by Luthor as a clear message to her.
Elsewhere, Sam has begun dating a woman named Gretchen, introducing her to his grandchildren in town as he takes her on a tour of Smallville. Yet Gretchen reveals she’s working for Luthor, incapacitating Sam in his last regular appearance, in order to bring him back to her boss in Metropolis. Clark encourages Jordan to reconcile with Sarah Cushing over their recent falling out. Jordan and Sarah mend fences, but decide not to be friends moving forward.
Luthor continues operating out of Bruno Mannheim’s laboratory hidden underneath the streets of Metropolis, with the captive Bizarro tentatively under his control. A flashback reveals that Luthor and his badly wounded henchman Otis discovered that every time Bizarro is killed, he revives stronger than before -- a process Luthor repeats to turn Bizarro into the ultimate weapon. This effectively transforms Bizarro into Doomsday, and with Sam taken off the board by Gretchen, Luthor plans to use his monster to eliminate Lois’ last line of defense: Superman.
Taking advantage of Smallville’s meteor shower celebration, Kyle publicly proposes to Chrissy. Chrissy happily accepts as Lana and John Henry look on. And Superman intercepts Lex Luthor when he approaches the Kent farm again -- only to be ambushed by Doomsday, who overpowers him before a terrified public. As Doomsday carries the defeated Superman into outer space, Clark thinks of his family and regains the strength to resume their fight, battling the creature on the Moon in an abrupt end to the season.
Developed for television by Greg Berlanti and Todd Helbing, Superman & Lois Season 3 is available to stream on the CW app and will be available to stream on Max July 28.