Deadpool made his way to the X-Mansion in 2016's Deadpool but was only able to enlist Colossus and Negasonic Teenage Warhead in his mission. This time around, he's gotten more suspicious as he visited the oddly quiet and seemingly empty mutant home. However, this time it's all explained why Deadpool can't get any of the "A-List" X-Men members.
It turns out the X-Men have been hiding from Deadpool. (Can you blame them?) About 20-30 minutes into the film, most of the characters from X-Men: Apocalypse and the forthcoming X-Men: Dark Phoenix are seen in a room. But Beast quietly closes the door before Deadpool can see them.
Director David Leitch told UPROXX the Dark Phoenix director, Simon Kinberg, who also produced Deadpool 2, filmed the X-Men scene on the Dark Phoenix set and sent it over to the Deadpool 2 team. So they weren't actually in the same X-Mansion IRL, but with some crafty editing, Deadpool 2 watchers ended up with a classic scene.
“That was a collaboration, a logistical puzzle, with Simon Kinberg and myself between our two movies,” says Leitch. "They were shooting Dark Phoenix at the same time. And he’s a producer on this, so he ended up getting the plate shot of them in the room. Then we got the shot of Ryan [Reynolds] on the other side. So the doors are the matte between the plate shot and them. So it was just sort of getting the visual effects to give us the right camera bits. Then they shot that for us, they brought it in, we comped it in in the background, then we shot it on our end. It was a fun little science project.”