After completing the scheduled amount of time exploring the moon, and filled with wierd events, the blast off goes wrong. The main power supply fails, and the rocket goes dark. There’s only enough oxygen and food supply for their return trip. How long will it take to get the rocket back into shape? Each crewman tries to conserve resources as they bide their time. Isn’t there something they can do? Unless the ship can be repaired soon, the crew will be doomed.
Then that wierd music returns. There’s somebody, or something banging on the spaceship. As suddenly as the power was lost, it comes back on. Everything will be OK… or will it? What was that tapping? What is that thing they see out there?