Supernatural’s Misha Collins thought he was only going to be a guest star on the show. Although the actor had a number of roles on both the big and small screen, Collins’ big break came when he appeared as Castiel in the season 4 premiere of Supernatural.

In the episode, titled “Lazarus Rising”, Castiel makes a grand entrance and leaves an immediate impression. Sent by God to resurrect Dean, and shrugging off a knife to the chest in his now iconic trench coat, the character was more prominently featured in his first scene than some of Collins’ other roles up to that point. But, in new remarks, the actor admits he didn’t really think it would be a long-term gig.

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As part of a recent interview with TV Line, in which Collins looked back on his long journey as Castiel and reflected on the character’s unforgettable entrance, the actor admitted that he didn’t really anticipate much when he signed on to be a part of Supernatural. Having not seen the show before, Collins noted that he wasn’t quite sure what to expect. You can read Collins’ full quote below.

“I’d never done a show like Supernatural. I really hadn’t watched the show, so I didn’t even know what the tone was, and I didn’t know what really was happening. I just sort of saw it as another guest spot that wasn’t a big deal, and I was kind of not putting a lot of stock in it, I guess.”

Collins is quick to add that his experience of Supernatural shifted in a positive direction once he saw the camaraderie between the cast and crew on set. Still, his initial assessment is grounded in the fact that Castiel was only meant to appear for a six-episode story arc. There’s also the fact that, up to that point, Supernatural had struggled with how to expand the series beyond the interactions of Sam and Dean. Other than the veteran hunter Bobby, who served as a father figure to the Winchester brothers, familiar faces would pop up for a few episodes each season. Or, in the case of the demon Ruby and the antagonistic Bela Talbot, they’d be killed off after failing to catch on with fans. Collins’ trajectory on the monster-hunting drama went in the opposite direction, as his performance of the higher-being quickly became a draw with audiences. Collins would end up sticking around for the rest of season 4 before being upped to a regular in the show’s fifth season.

Collins has credited his promotion to the positive feedback received from fans. There’s an argument to be made that, if not for the welcoming reception Castiel received, Supernatural might have ultimately had a very different history. Despite the fact that the brotherly bond between Sam and Dean would always remain the central focus, it’s hard to imagine that the drama could have sustained itself for another decade based on that alone. Castiel made his debut at just the right time, opening the door for other future characters such as Crowley and Jack to become protagonists in their own right. Castiel also gave Supernatural a shot in the arm in a different sense, as the character’s interactions with Dean created a fandom all its own. In the end, the role that Collins saw as just another guest stint proved to be career-altering.

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Source: TV Line