Midvalley was startled when he heard the sound of gunfire and broken glass. Neither was such an unusual sound in Niflheim, but it generally didn't sound like it was coming from the hallway right outside. And had someone been speaking first? Midvalley thought it was very unlikely that Niflheim had come under attack from Asgardian gunmen but he walked to the door and opened it cautiously.
To his surprise he saw Mitch, that drummer from Asgard, who was holding a gun he had evidently used to shoot out a window. And Sal was there. Sal had a long-time obsession with Mitch, so maybe this was a personal argument that wasn't Midvalley's business, but from the way they were lurking by Jazz's door he suspected otherwise. Had they planned to attack Jazz? Surely they would have realized those guns were fairly useless against a giant armored robot.