A human physician who exchanged posts with Phlox through the Interspecies Medical Exchange and later heads Cold Station 12.
Doctor Jeremy Lucas takes part in the Interspecies Medical Exchange, serving on Denobula while Phlox serves aboard Enterprise. In Dear Doctor, Phlox replies to one of his letters and describes life among the humans, and in Doctor's Orders Phlox writes to him again while the human crew sleeps through a dangerous region of space.
Lucas finally appears in Cold Station 12 as the head of the Starfleet medical facility that stores frozen embryos and deadly pathogens. When Arik Soong and his Augments seize the station, Lucas is tortured by Malik and gives up the embryo access code after Phlox is threatened.
He then tells Archer how the pathogens Malik has released can still be contained, but only within a few minutes. His long correspondence with Phlox gives the series a gentle running thread about friendship across species.