Samantha Malone is Tyler's girlfriend. Tyler's relationship with Sam weakens as he has to leave during their anniversary, and Sam feels scared for Tyler's health. Towards the end of the story, Sam arrives at Tyler's work and says that she is going to her father's vineyard, asking Tyler to come with her. At this moment, a "leap of faith" is performed as Tyler chooses either Sam or his job.
Source: Wikipedia, "[en.wikipedia.org/wiki/Fahrenheit_%282005_video_game%29%23Plot Fahrenheit (2005 video game)]", available under the CC-BY-SA License.