TV Supernatural's Jensen Ackles talks filming Castiel's goodbye scene Ackles reveals the origin of the handprint. By Samantha Highfill Samantha Highfill Samantha is a writer based in Los Angeles. Television is her one true love, and she tweets about it. A lot. EW's editorial guidelines Published on November 17, 2020 01:00PM EST EW spoke with Ackles about filming the final season, and the moments when it started to hit him that the show was actually ending. Not surprisingly, one of those moments came when Castiel (Misha Collins) sacrificed himself to save Dean in episode 18, thereby marking Collins' last scene on the series. "The scene between Cas and Dean, basically Cas's goodbye scene, it started to hit a little bit that day," says Ackles. "Knowing that this was Misha's kind of tearful goodbye to Cas was tough. I did my best to hold it together on my end." As Ackles puts it, that scene made the show's ending "hard to ignore." As for one of the scene's great callback moments, when Castiel shoves Dean out of the Empty's path and leaves behind a handprint on his shoulder reminiscent of when he first pulled Dean from hell, Ackles remembers that being something they came up with on the fly. "I kind of want to say that that was Misha's idea," Ackles says. "I feel like that was a on-the-day idea." Turns out, Ackles was correct about half of that. EW got in touch with episode writer Robert Berens and director Richard Speight Jr. who confirmed that it was an on-the-day idea, though they said it was "a group realization/inspiration by Rich, Misha and Jensen, triggered by a location move that happened the very day they shot the scene." For more, watch the video with Ackles above. Related content: Celebrating Supernatural's humanity in its time of dying Supernatural boss says series finale is 'more of an old-school episode' Robert Singer on what to expect from Supernatural's series finale