Dr. Moira MacTaggart is one of the foremost authorities on human genetic mutation. She lives and works on Muir Island, off the coast of Scotland. In the books, she is now deceased, the first human casualty of the Legacy virus. Rahne Sinclair, her former ward, was a member of the New Mutants, X-Force, and X-Factor. Dr. McTaggart was known for her fierce determination, her sympathy to the mutant cause, and her ability to argue even Professor Xavier down.Alternately, in X-Men: First Class, Agent Moira McTaggart is a resourceful young operative for the CIA, assigned to watch the Hellfire Club in Las Vegas, a casino the US government believed was a front for Communist activity. After sneaking in the club, Agent McTaggart is able to access the club's secret rooms and confirm that The Hellfire Club does have Communist connections. Before leaving the casino and reporting back to her superiors, she catches a glimpse of Emma Frost in full diamond mutation, which causes her to seek out genetic mutations expert Charles Xavier.Agent McTaggart is one of a few CIA agents who believe mutants are not automatically a threat to national security, and she is with the mutants who eventually become X-Men and The Brotherhood during the Cuban Missile Crisis. She fires on Erik Lensherr to distract him from sending a volley of missiles back at the ships which attacked the mutants, and it is one of her deflected bullets which causes Charles Xavier's paraplegia.