This is about the part of us that we never see, hence the title. I once did a photographic project at college which involved taking portraits of people that I knew there, without including their faces. This, in many ways, is similar. The back of their heads makes the imagination work harder, and it seems to me to be not really necessary to see their face. You can just imagine what they're like without that information. These have been taken around the world over a few years.