Agent 201
Agent 201 was a female Human whose ancestors were abducted from Earth in the 4th millennium BC and taken to a hidden planet 1,000 light years away.

Agent 201 was sent to Earth prior 1968 with her partner Agent 347 to keep Earth from destroying itself with nuclear weapons.

The two of them used advanced alien technology, hidden in Apt. 12-B on 811 East 68th Street in New York City. They hired Roberta Lincoln as a , under the guise of "research for a new encyclopedia".  Initially, when mistaken for 201 and asked where 347 was, an oblivious Roberta Lincoln quipped, "With 348?" 

Both Agents 201 and 347 were killed in an automobile accident in 1968. When contact was lost, their superiors sent Supervisor 194, who took over their mission. ()

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Humans