The Last Days on Mars

On the last day of the first manned mission to Mars, a crew member believes he has made an astounding discovery - fossilized evidence of alien life. Unwilling to let the relief crew claim all the glory, he disobeys orders to pack up and goes out on an unauthorized expedition to collect further samples. As crew members start to vanish one by one, they begin to suspect that the life-form they have discovered is not yet dead.