Star Trek Discovery has ben rebooted and warping around the universe at light speed. One of the most popular original series episodes was Let that Be Your Last Battlefield, where Kirk and the Enterprise crew encounter an alien race with skin evenly black on one side and white on the other. One of the men is a fugitive, one the poilce officer in pursuit. The chase has been ongoing for over 50,000 years. Till finally, they arrive back on their home planet.
Science Officer Spock makes a logical but startling fact about the two men. On one man, his face is black on the left side of his face. The second mans face is black on the right side of his face.
At the beginning of season two, the Star Trek Discovery crew encounters another pair of aliens from the planet Cheron. This time, they are both female.