We’re now back at the scene that was used for the pre-title sequence.   We see that Julia wasn’t the person shot and Ethan goes looking for her.   Additional shots are added to the scene.  Like in all the Mission: Impossible movies, a mask was used to deceive the audience.  We thought we saw one thing at the beginning of the film but really saw something different. After this scene, Musgrave talks to Ethan and exposes that Musgrave is the bad guy in the IMF.