Warning: This article contains spoilers for Superman & Lois, season 4, episode 3, "Always My Hero."

Superman & Lois didn't take long to bring Superman (Tyler Hoechlin) back from the dead in the final season — but one major character had to sacrifice himself in order for the Man of Steel to return.

Monday's intense episode 3, "Always My Hero," featured an emotional twist for the final season that began in the opening montage, as the Kents — Lois (Elizabeth Tulloch), Jordan (Alex Garfin), and Jonathan (Michael Bishop) — prepared for a funeral. It seemed to be for Clark, now that his heartless body was being kept in the Fortress of Solitude. But the end of the hour revealed it was actually General Sam Lane's (Dylan Walsh) funeral, after he died a hero's death in the episode's climax.

Colin Bentley/The CW

After Sam got shot by a rogue Department of Defense soldier who was being blackmailed by Lex Luthor (Michael Cudlitz), Sam made a split-second decision to inject himself with the vial of serum created from Superman's blood. He then sacrificed himself when Lex ordered Doomsday to kill him, because moments before, he had clued John Henry (Wolé Parks) into his plan to use his juiced-up heart to revive Superman. Sam had originally intended to use a donor's heart combined with the serum, but his plan changed when Doomsday arrived and he ran out of time.

His sacrifice appeared to not be in vain: His heart was transplanted into Superman's body and the episode ended with Superman opening his eyes and gasping. But the hologram of Superman's mother Lara (Mariana Klaveno) warned John Henry that she was worried the serum-enhanced human heart wouldn't work properly, so there could be complications moving forward.

Bettina Strauss/CW/Everett

Walsh had been a series regular on Superman & Lois since the series premiere, but was cut back for the final season due to decreased budget along with Emmanuelle Chriqui (as Lana Lang), Erik Valdez (as Kyle Cushing), Inde Navarrette (as Sarah), Parks (as John Henry Irons), Tayler Buck (as Natalie), and Sofia Hasmik (as Chrissy Beppo).

"Unfortunately, with the state of the business, we had to do it," showrunner Todd Helbing previously told EW. "That was one of the decisions that unfortunately was made [to make the final season happen]." Showrunner Brent Fletcher agreed, adding, "That was a lot of the secret sauce that helped us get this done."

"But when we talked to all the cast members, everybody understood it, and they were still committed to being in as many episodes as we could put them in," Helbing added. "It also afforded us [the opportunity] wrap all these storylines up in a really satisfactory way. People get a full meal, so the episodes they were in, they're part of the storyline in the way that maybe they weren't the past three seasons, and it's really satisfying."

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Elsewhere in this episode (which was directed by Tulloch's husband David Giuntoli), Jonathan finally got powers — all of them, all at once — and excelled at using them immediately, to no one's surprise and Jonathan's disappointment. John Henry and Natalie gave up their goal of living a normal life to join up with the DOD full-time to help protect the world in Superman's absence — and officially got their call names of Steel and Starlight. And Lex Luthor revealed to Jordan that Lois had picked Jon as her favorite son (yikes).

Plus, we also saw important flashbacks to Lois and Clark revealing his secret identity as Superman to Sam, Clark asking Sam for his blessing to marry Lois (and Sam refusing), and Lois and Clark's wedding day, when Sam ultimately (and begrudgingly) gave his blessing to their union. Hoechlin previously teased those flashbacks, telling EW, "There's one flashback in particular with Dylan Walsh that I had an unbelievable time with, it was so much fun."

The final season of Superman & Lois airs Mondays at 8 p.m. ET/PT on The CW.