Supernatural kicked off its lucky 13th season on an emotional note, with Sam and Dean saying a heartbreaking farewell to Castiel — along with all the other allies they've lost in recent months — and reluctantly taking Lucifer's newborn son, Jack (who happens to be a full-grown dude) under their wing.

Luckily for fans, we already know that Cas is coming back this season, so we don't need to mourn Misha Collins' resilient angel — but for the Winchesters, that loss is potent and, as far as they know, permanent.

He’s not coming back real soon, and it influences, greatly, Dean’s state of mind," says producer Brad Buckner, who was joined by his writing partner Eugenie Ross-Leming and Star Jared Padalecki for a press screening of the Season 13 premiere before it aired.

That grief is compounded by Dean's feeling that the Winchesters are truly alone in this fight — as demonstrated by his desperate prayer to Chuck to bring back Cas and their mother, Mary, which once again went unanswered.

We’re conditioned to that Omen kind of thing, and this kid has got qualities that while he’s obviously can be potentially dangerous, he is curious and inquisitive and willing to believe, and that Sam takes as adding up those positives.