The Mission: Impossible movies aren’t famous for their scrupulous realism, but they at least tend to stay just this side of plausible. The fun of following their twisty plots, full of double-crosses and surprise reveals, is the way they let you think you know what’s going on and then pull the rug out from under you: They don’t keep you in the dark so much as point you toward the wrong light.

But there’s one part of Mission: Impossible—Fallout that still doesn’t add up. (Spoilers follow.) And that’s how Benji Dunn (Simon Pegg) and Solomon Lane (Sean Harris) swap places. In the catacombs underneath London, Ethan Hunt and his team hatch a plan to exchange the villain for the stolen plutonium that serves as the movie’s MacGuffin, only instead of letting the real Lane out of their sight, they hand over Benji in a Solomon Lane mask. After the team departs, leaving Lane guarded by Henry Cavill’s CIA thug, Walker, the two engage in a chummy conversation in which Walker reveals that he is the movie’s mysterious murderous mastermind, John Lark. Surprise! The Lane who stayed behind is a masked Benji, and the one who walked out the door—who we thought was Benji in a Solomon Lane mask—was the real McCoy.

There’s just one problem: The movie doesn’t offer any way it could have happened. Director Christopher McQuarrie stages Benji’s en-masking and departure in a single, unbroken shot that ends with the camera lingering on the real Lane, sitting unconscious in a chair as the entire IMF team files past him. There’s no convenient cutaway, no stray distraction that could have allowed for a swap, which means it’s not a trick so much as it is a cheat. One never wants to sound like Misery’s Annie Wilkes, but Solomon Lane did not get out of that cockadoody chair.

Slate asked McQuarrie if we were missing something, and he admitted that we were not.

“We spent ages, and I mean ages, working out how logically it would have worked,” McQuarrie said, “and how they could have hidden it even if somebody was watching it happen. We devised all the sleight of hand and shot it all. And there’s just simply nowhere in the movie for it. There’s nowhere that doesn’t kill the momentum of the movie. And we thought, ‘It’s in our pocket if people ask. Let’s see if they ask.’ And nobody did. You’re the first person who has ever asked.” Some shots from this sequence will, at least, appear on the DVD, he said, though not as a full deleted scene.

McQuarrie explained that’s a common approach in the Mission: Impossible films, where even information necessary to the story is cut out if it slows down the pace. “There’s a few times in the movie when we were testing it, or when we were showing it for friends and family, where someone would ask a question, ‘I was confused about this. Where did this thing go?’ Or, ‘Where was that during the whole movie?’ [Editor] Eddie Hamilton was standing next to me when somebody asked a question like that, and he said, quite astutely, ‘Did it matter?’ And the person thought about it for a beat and said, ‘No, not really.’ And he was like, ‘Yup, that’s why it’s not in the movie.’ We have the answer. We shot it, and we put it in the first [cut] and people were just dozing off during those scenes. They didn’t give a fuck.”