Warning: Spoilers ahead! Do not proceed unless you’ve watched the “House of the Dragon” Season 3 premiere. 

Goodnight, sweet prince.

“House of the Dragon” Season 3 opens by brutally killing another main character: Prince Jacaerys “Jace” Velaryon (Harry Collett), the firstborn son of Queen Rhaenyra Targaryen (Emma D’Arcy) and the heir apparent.

In the episode, Rhaenyra is informed that ships are gathering and preparing to fight. She wants to fly her dragon, Syrax, into the naval battle — which is called The Battle of the Gullet.

Jace insists that, because his mother is the queen, she shouldn’t risk going. He locks Rhaenyra in her rooms and disobeys her orders, flying his dragon, Vermax, out to enter the battle himself. 

When Jace and Vermax fly over the water where the ships are fighting, his cousin, Lady Rhaena Targaryen (Phoebe Campbell), flies in on Sheepstealer, the wild dragon she recently tamed.

Unfortunately, Jace had no idea that Rhaena was coming to aid him, and he gets both surprised and distracted. 

Since she’s new at flying a dragon and Sheepstealer is feral, Rhaena has limited control over the dragon. The beast keeps spitting fire at people erratically — no matter what side of the war they’re on. 

Rhaena and Sheepstealer distract Jace, leading to Vermax getting shot down by enemies on the ships below. 

Jace falls off a wounded Vermax. As he floats in the water, archers standing on a nearby ship shoot him in the chest with a bunch of arrows, killing him. His body is left floating in the water. 

During an HBO press conference Page Six attended, Collett said Jace had “reached his boiling point,” which is why he locked his mother in her room and entered the battle against her orders.

“He’s very determined. He knows what he wants, he knows what has to do and he is not gonna stop anyone in his way to get it,” he added.

But, in the end, Jace was stopped — by a distracting dragon and a hail of arrows.

The show is set nearly 200 years before the events of “Game of Thrones.” In the years after “House of the Dragon,” the Battle of the Gullet becomes known as the bloodiest sea battle in Westeros history. 

The main forces fighting in the battle are the Triarchy, led by Sharako Lohar (Abigail Thorn) and Tyland Lannister (Jefferson Hall), violently clashing against Jace’s grandfather, Corlys Velaryon (Steve Toussaint), and his forces.

“House of the Dragon” follows Rhaenyra and her allies — which includes Corlys — fighting for control over the Iron Throne.

In true “House of the Dragon” style, Jace isn’t the only death the Season 3 opener contained.

Sharako and Tyland also get killed in the Battle of the Gullet.

Tyland’s twin, Jason Lannister (also Hall) also gets beheaded offscreen, earlier in the episode. 

Jace is Rhaenyra’s second son to die, after her half-brother Aemond Targaryen’s (Ewan Mitchell) dragon ate her son Lucerys “Luke” Velaryon (Elliot Grihault), at the end of Season 1. 

For those keeping count: Rhaenyra started with five sons, and now she has three. Her oldest three sons (including Jace and Luke) were fathered by Harwin Strong (Ryan Corr). Her younger two sons (who haven’t been onscreen much) were fathered by her uncle-slash-husband, Daemon Targaryen (Matt Smith).

During a press conference attended by Page Six, showrunner Ryan Condal said, “It’s a Shakespearean family tragedy,” and added, “things get darker and a bit bleaker.”

This is the penultimate season, as HBO has announced the show will end with a forthcoming Season 4.

“There is a darker mood that you’ll continue to see unfold over the rest of not just this season, but going into the final season as well,” Condal said.

“House of the Dragon” airs Sundays at 9 p.m. on HBO.