It had been eighteen hours since the lights went out.

It took the combined strength of myself, Petty Officer Reilly, and Doctor Meyer to force the door open. The Captain’s quarters were quiet, and so dark that we had to light our way with our suit-mounted flashlights. I nearly lost my balance on a dry-erase pen, left on the floor to roll under my boot and go caroming off into a dark corner.

            “There,” Reilly pointed with his flashlight.

The Captain slumped against the wall, a tourniquet tight around his throat and his face swollen almost beyond recognition.

            “What’s that?” I asked, pointing to the wall above him.

Writ large in our Captain’s handwriting, a message had been inked on the wall:

The onboard AI has calculated that the four of us would run out of oxygen 43 minutes before rescue arrives.