It's the beginning of the end for The CW's "Supernatural."

The TV series is kicking off its 15th and final season this fall, and The CW has released a promotional poster that appears to hint at what's to come for the long-suffering, demon-hunting Winchester brothers.

The poster was tweeted out this week by the official "Supernatural" Twitter account, with the message "One last ride" -- a homage to one of the show's beloved characters, "Baby," a 1967 Chevrolet Impala.

"As it is written, so it shall end," the poster reads. It features images of the show's stars -- Jensen Ackles, Jared Padalecki, Misha Collins and Alexander Calvert -- against a backdrop of fire, angel wings, an anti-demon possession symbol and a stairway that appears to lead to heaven.

The poster is a nod to the Season 14 cliff-hanger.

If you're not in the know, "Supernatural" follows the journey of the Winchester brothers Sam (played by Padalecki) and Dean (played by Ackles) as they battle monsters, angels and, sometimes, each other in an effort to save the world. Along the way, they befriended an angel, Castiel (Collins) and, more recently, a Nephilim, the offspring of Lucifer and a human (Calvert).

In the season 14 season finale, Chuck -- who we learn is the creator of all -- snapped his fingers and released demons from hell, leaving Sam, Dean and Castiel to fight off the monsters.

Chuck's parting line:

"Story's over. Welcome to the end."

Already speculation has begun on social media about the poster's symbolism, and what it says about the final season: Will Sam and Dean Winchester die? Will they climb a stairway to heaven? Will Baby be destroyed?

In an interview with Entertainment Tonight, Padalecki said he and the cast didn't know how the show would end.

"I think, to a certain degree, the fandom won't be happy with any ending. Nor will we, to a certain degree. I don't think any of us want to see this show go."

But The CW has given fans a hint with the poster. And it looks like the Winchesters will be in one hell of a fight to the end.

The stars of the show are also using attention around the series finale to help provide relief for victims of Hurricane Dorian.

Ackles, Padalecki and Collins also teamed up with Hot Topic to create a limited-edition "End of the Road" T-shirt to help provide relief for victims of Hurricane Dorian.

Collins took to Twitter Saturday to announce 100% of the proceeds of the sale of the shirt through Sunday will go to his charity, Random Acts, to provide aid to hurricane victims.