Thomas Milligan

Tom Milligan was a doctor who worked for the NHS in 2008. When the Master brought the Toclafane to Earth he became a fugitive. In 2009 he met Martha Jones when she returned to England and took her to see Professor Docherty. When the Master tracked them down, he killed Tom with his laser screwdriver.

When the Master's Paradox Machine was used to reverse time to 2008, Martha phoned Tom and hung up. (DW: Last of the Time Lords)