Within the series' narrative, Martha begins as a medical student who becomes The Doctor's time travelling companion after an incident at the hospital where she works. After well over a year (from the perspective of The Doctor and herself) travelling with The Doctor, Martha parts from The Doctor's company as she recognises how unhealthy their relationship has become. After returning to life on Earth, becoming engaged and finishing her medical degree, Martha finds a newfound level of independence when she is recruited into the paranormal military organisations UNIT, and briefly Torchwood. Having faced the end of the world single-handedly during her time with The Doctor, Martha is recognised for her skills both in the field and in medicine.