Star Trek: Discovery.A new episode of the CBS All Access series drops Christmas Eve, but ET has an early present in the form of sneak peek. Titled «Su'Kal,» the episode sees USS Discovery venturing to the Verubin Nebula, where Burnham, Saru and Culber make a shocking realization about the origin of the Burn as the rest of the crew faces an unexpected threat. In ET's exclusive clip, Stamets (Anthony Rapp) expresses his worry over Culber (Wilson Cruz) embarking on his dangerous new mission.