Later this week (once I complete it) I’ll be reviewing the Leviathan DLC for BioWare’s epic Mass Effect 3, but in the meantime, here’s a post to help other players like me, who are (uselessly) trying to play the DLC!
Load your last saved game (as long as it’s not the save before the last mission “The Return”), board the Normandy, and check your messages. You’ll have one there from good ol’ Admiral Hackett regarding a Dr. Bryson. Go to your Galaxy Map, and voilà! You can start the hunt for the mysterious Leviathan.