The last person in space heard knocking on an airlock door.
You pulled yourself through the empty space station toward the sound. Again you heard the knocking. Three thudding knocks. You reached the airlock before the knocks sounded once more. Through the window, you looked into the airlock. No one was in the airlock. Not that you expected anyone to be there since you were the last one left on the station.
Left behind when the emergency evacuation order came through and there were one too many people for the return capsules. Everyone had stared at each other in horror as you all realized someone would have to stay. There was no fighting, no posturing, no exceptions. A simple lottery, short straw stays, was improvised with strips of paper. Everyone drew and you lost.
The knocking happened again you to pushed away from the door startled. As you impacted on the wall behind you, you realized the knocking must be coming from outside the station. Some part of the station has come loose, you thought, it could damage something if I don’t secure it. You had several months of air and supplies but it would be all worthless if something knocked a hole in the station.
You went through the nearly impossible task of putting on an extravehicular suit and mobility harness alone. There were latches and seals and straps that were not meant to be closed from inside the suit. For an hour, you struggled with it, all the while hearing the repeated knocking. At first, you cringed at every knock hoping the station could take the hits. By the time you were suited up and ready to cycle the airlock, you had started counting the seconds between the knocks.
As the air was evacuated from the airlock, silence descended around you. You clipped a safety cable from your suit to the inside of the airlock. The outer door swung open and you carefully exited. You looked around for whatever had been knocking against the station but there was nothing. The airlock was at the far end of the station, away from the solar panels or cross modules, meant for docking with the shuttle. The robot arm for moving cargo from the shuttle was locked down, unmovable.
Your safety cable suddenly went slack. By the time you finished turning, the outer door was closed. By the time you reached the outer door, the inner door was open. You struggled with the outer door but safety systems prevented both doors from opening at the same time. Carefully you made your way around the outside of the space station to another airlock. It also refused to open. As did the third airlock.
Stranded in space, locked out of the station, floating with limited air, you began to feel hopelessness creep into your mind. For an hour, you stared into an airlock window willing the inner door to close. Then you saw a shape move past the open door. Just a blur in your vision but it was something. It, you realized, was what had opened the airlocks. It was what had been knocking. It was what you let in.
You waited, staring through the window until you saw it flash by again and then you knocked on the airlock door. It returned to the airlock. Long arms with too many joints pulled it into the airlock. You knocked again. It flinched back before jerking forward to stare back at you through the window. Large multicolor faceted eyes regarded you from an alien face. You knocked again. The alien tilted its head in an almost human gesture and then it left the airlock.
For the next several hours, you continued to knock trying to get its attention but anytime is passed the airlock it would only glance inside before continuing on. With your air supply almost exhausted you began continuously knocking on the airlock. It came then and watched you for the longest time. When you began to labor with each breath it moved closer to the window. The last thing you saw was its eyes staring at you without apparent care.