‘House of the Dragon’ kills off unexpected beloved character in season 3 premiere

The Battle of the Gullet was just as deadly as promised.

On Sunday, the long-awaited season 3 of House of the Dragon aired and three major characters were dead, including Jace (Harry Collett).

As an adaptation of George R. R. Martin's Fire & Blood, some fans knew what to expect from the new House of the Dragon episode, since Jace dies during the well-known naval battle in Martin's book.

The death of Jason Lannister (Jefferson Hall) is also to be expected based on Fire & Blood. Sharako Lohar (Abigail Thorn), though, survives the Battle of the Gullet in the book, so her death at Alyn of Hull's (Abubakar Salim) hands came as a surprise.

Ahead of the premiere of season 3, star Emma D'Arcy, who plays Rhaenyra Targaryen and is mom to Jace, tells PEOPLE how the death of Rhaenyra's second son (Luke died in the season 1 finale) will affect the rightful heir to the Iron Throne.

"I think Jace's death is honestly a sort of unquantifiable loss," D'Arcy says, adding, "I think, really, there was a shared kind of understanding, there was an intimacy there that I don't think [is] replicated anywhere else."

The tragedy propels Rhaenyra forward in her quest for the Iron Throne, D'Arcy says. "Sometimes, grief simplifies things, and I think there is a kind of nihilism offered to Rhaenyra in this moment that I think allows her to be more brutal. I think there's a black-and-white thinking sometimes that comes with grief."

The "vengeance" she demands in the wake of Jace's death "requires Daemon's violence," D'Arcy continues, referring to their costar and onscreen husband, Matt Smith.

"I think there's a clarity actually that comes with Jace's death, not least because again, this is a political family, and if you secure your legacy, you preserve the memory of those around you. And her name will be in a ledger somewhere along with her son."

"I think that makes her inheritance all the more meaningful," D'Arcy says as now, Jace's legacy and Rhaenyra's are even more "tied together."