On May 13th, the documentary What We Left Behind: Looking Back at Star Trek: Deep Space Nine will hit theaters for one night only. Today, we’re thrilled to debut an exclusive clip from the film where the actors reflect on the grueling makeup process. Because exotic-looking aliens have been so engrained with the idea of Star Trek, we tend not to think about how that makeup affects the actors. This clip provides some nice insight into what it was like for folks like Michael Dorn (Worf) or Rene Auberjonois (Odo) who had to put on loads of prosthetics …