Explosions on Omega and Shepard's not the reason? That's a new one. He's on his way though, because explosions are never a good thing and it's usually Shepard that gets shit taken care of in the first place.

So he's on his way when he gets the ping on the Normandy's usual frequency. That piques his interest even more. He's bumping through the crowd of people rushing away from the site of the explosion and the shuttle bay while checking his omni-tool for that singular signal from before when he catches sight of a familiar salarian.

He pushes through a few people and makes his way over.

"Mordin? Where the hell have you been? We thought you'd gone AWOL."