Sometimes, even the most perfect casting choices in movies need a little help, and sometimes they almost don’t happen. Can you imagine the Lord of the Rings movies with Gandalf being played by someone other than Sir Ian McKellen? Or what if McKellen hadn’t played Magneto in Bryan Singer’s X-Men franchise? Would they even be worth watching at that point, and who would they have gotten?

Luckily, we don’t have to think about that because he was cast as both iconic characters, but in an interview with People, the current Mr. Holmes star tells the story of how he very nearly didn’t play Gandalf or Magneto, thanks to Tom Cruise. Yes, friends, Tom Cruise is the villain of the piece. McKellen was offered a role in Mission: Impossible II, which was directed by John Woo, but the actor wasn’t allowed to read the full script, only his scenes. Since he couldn’t get a grasp of the movie from those, he turned it down, despite his agent telling him he’s crazy.

The very next day, Sir Ian continues, he was offered both Magneto and Gandalf. Both of them! What an amazing stoke of luck! He also goes on to say that X-Men overran to the point that it looked like he wouldn’t get to go to New Zealand to play the famous Grey Wizard, but Peter Jackson held the part for him and Bryan Singer did what he could to ensure McKellen got to do both.

Depending on what part McKellen was offered for M:I2, it’s pretty unlikely he’d ever be back for future films, but he’s played Gandalf in six features and Magneto in four, minus cameos. Not only that, but the world would have been deprived from the delightful friendship between McKellen and Patrick Stewart, who struck up a bond in the X films. Now that REALLY would have been a travesty.

You can read the whole account, plus the full interview with Ian McKellen, in People. And you can listen to McKellen himself on this new episode of the Nerdist Podcast.