The Gate of Lemnos. Francis Jarman

The Gate of Lemnos is the entrance to a new world, one of the wonders of the universe, and Terra's only planetary colony containing alien life forms. Burk has been sent there with a mission to accomplish, and a sinister secret to expose. But there are those who are determined to stop him, both on and off the great spaceship, Starstretcher, and no one–NO ONE!–can be trusted. A science fiction suspense tale.