Stefan DeSeve

From Memory Alpha, the free Star Trek reference.

Stefan DeSeve was a Human Starfleet officer who defected to the Romulan Empire in about 2349. He was an ensign at the time.

He originally defected because he considered the Romulans to have clear moral values and an absolute certainty about the purpose of life, something he called a "strict moral compass". After living on Romulus for twenty years he became disillusioned with the Romulan system. Their desire for conquest and the deception used for this purpose did not sit well with him.

In 2369, he was a member of the Romulan underground movement, and decided to return to the Federation to deliver a message from Ambassador Spock. Upon arrival, he was arrested for treason. DeSeve insisted on speaking to Captain Jean-Luc Picard and told him he had a message for him. DeSeve said that a Corvallen freighter would arrive shortly in the Kaleb sector carrying Vice-proconsul M'ret, who had decided to defect to the Federation.. At first Picard was highly suspect of DeSeve, but decided to follow through with the plan and the defection of M'ret was successful. (TNG: "Face of the Enemy")

DeSeve was played by Barry Lynch.

[edit] Background Information

In a deleted scene, DeSeve was in his quarters trying to use a replicator to get some coffee. However, he had spent so many years living among Romulans that he had forgotten much of his native language, and had difficulty remembering how to actually pronounce the word.