SPOILER ALERT: This article contains spoilers for the Season 3 premiere of “House of the Dragon,” now streaming on HBO Max.

“House of the Dragon” is back, with another main character being killed in epic fashion. In the Season 3 premiere of the “Game of Thrones,” and Rhaenyra Targaryen (Emma D’Arcy) loses yet another child. After her young son Lucerys died in the Season 1 finale, her eldest son Jace (Harry Collett) was killed in the Battle of the Gullet along with his dragon, Vermax.

The season premiere wastes no time jumping right back into the action as Rhaenyra’s forces, aka the Blacks, are still at war with the Greens, the King’s Landing loyalists under King Aegon II (Tom Glynn-Carney) and his mother Alicent Hightower (Olivia Cooke). Rhaenyra’s army, led by her uncle and husband Daemon (Matt Smith), is gaining strength as they’re joined by a grizzled pack of House Stark northmen known as the Winter Wolves. Plus, they have more dragonriders than the Greens after they bolstered their numbers with several dragonseeds, Targaryen bastards who can command the fire-breathing beasts. Skilled sailors Corlys Velaryon (Steve Toussaint) and his bastard son Addam of Hull (Abubakar Salim) lead the Black’s navy against the Triarchy, a group of pirates led by Sharako Lohar (Abigail Thorn) who pledged fealty to the Greens. (Read Variety’s interview with Loni Peristere, the episode’s director.)

Over in King’s Landing, things aren’t going so great. Aegon, who was burned and crippled in Season 2, fled with Larys Strong (Matthew Needham), leaving his cruel, one-eyed brother Aemond (Ewan Mitchell) to sit on the Iron Throne. After an extremely awkward mother-son kiss, Alicent convinces Aemond to fly to Harrenhal and hunt down Daemon. That leaves the Iron Throne empty for Rhaenyra to take it — a plan she had secretly hatched with Alicent last season. But before Rhaenyra can destroy the encroaching Triarchy ships then fly to King’s Landing, her son Jace has her locked in her chambers at Dragonstone to protect her. Surely this will go well for him!

Jace, Daemon’s daughter Baela (Bethany Antonia) and their dragons join the Battle of the Gullet, which is turning into full-scale carnage. Both sides are losing ships and suffering massive casualties. Lohar boards Corlys’ ship and nearly kills him, but Addam saves his father’s life and kills the pirate in a water-logged fight. High above, Jace and Baela are unexpectedly joined by Baela’s sister Rhaena (Phoebe Campbell), who has bonded with the rogue dragon Sheepstealer, and is unable to control the monster. Sheepstealer turns on the fellow dragons, causing them to fly out of combat and dodge its massive claws. Jace’s dragon Vermax is then struck with a ballista bolt, dragging Jace into the water. As Vermax struggles to stay above water and begins to drown, Jace frees himself from his mount and reaches the surface. However, he’s struck unceremoniously by three arrows from a nearby ship, killing him.

“It was really hard to act dead — it’s actually one of the hardest acting I’ve ever done in my life,” Collett says of his watery death scene. “It was really fun, but also really challenging trying to keep my eyes open in the water and staying afloat, while also not getting any up my nose. Otherwise, I’d cough, and obviously I’m not dead if I cough. So that was quite challenging.”

Showrunner Ryan Condal had to cut the Battle of the Gullet from Season 2 due to budget constraints, and the team goes all-out in the Season 3 premiere. Collett reveals that he was told back in Season 1 that his run on the show would last only two seasons.

“I knew my fate already, and was taking the days as they come and enjoying myself and just being grateful to be on this show in the first place,” he says. “When I read Season 2, normally Ryan calls you to tell you what is gonna happen this season. I didn’t get a call, and I was like, ‘Is he just waiting until like we get to the script read?’ But, no, it got skipped in Season 2, which I’m very grateful for. It’s great that it gets to be the first episode that people see for this season.”

With Jace dead, Rhaenyra has only her sons Joffrey, Aegon III and Viserys II remaining, though they’re too young to join the war. With her navy decimated, she’ll need all the help she can get to take King’s Landing and begin to rule Westeros.