How does a person know their gender? Do they see themselves as male or female, or somewhere in between? More and more people around the world do not identify with the gender they were assigned to at birth. Increasingly, people are expressing their gender identity outside of the 'norms', and the lines of gender are becoming more blurred than ever. This film explores what it actually means to be transgender, and what happens when a person transitions psychologically, physically and biologically. We follow a number of transgender people going through their own transition. From a socially transitioning transwoman to two young transmen embarking on hormones, to a transwoman going through gender confirmation surgery - we get a snapshot into what transitioning and being transgender is really like from those living it. We also hear from experts in the field of gender and find out how modern medicine is helping people to transition their gender. And we explore where gender identity actually comes from.