AceShowbiz -

Next week on "Game of Thrones", it's the moment that has been dreaded the most by Jon Snow since the beginning of the season. After refusing Jon's proposal to seal off Castle Black, Ser Alliser Thorne, now the acting Lord Commander of the Night's Watch, will lead the watchers against the wildings sent by Mance Rayder.

"Tonight, we fight," Thorne tells the watchers, who are outnumbered. "And when the sun rises I promise you... Castle Black will stand," he continues saying in a preview video for the penultimate episode of season 4.

Titled "The Watchers of the Wall", the new episode will air Sunday, June 8 at 9/8c on HBO. The official synopsis doesn't reveal much, but says, "Jon Snow and the rest of the Night's Watch face the biggest challenge to the Wall yet."

The upcoming epic battle comes after [SPOILER ALERT!] the showdown between Gregor Clegane a.k.a. the Mountain and Oberyn Martell that ended up with the death of Prince Oberyn. Speaking of the brutal ending for his character, Pedro Pascal said, "It was something I was prepared for all along, but still it is such a brutal twist in the story."

To fans who may be devastated by Oberyn's death, he said, "They might be disappointed that I'm dead, but in the actual execution of that death, I hope that their expectations are totally fulfilled."

Tyrion Lannister, meanwhile, will face execution after demanding trial by combat, with Oberyn acting as his champion.