A Dark time for the Human race has come. The Earth is in danger. Aliens are going to capture planet Earth (as they always are). It's clear to see that they are ugly, loathsome, vile and and have the worst designs of all conquerers. Women will be eaten away, the brains of intelligent men will be worked into liquid assigned to wash their nasty spaceships, children will be taken away for terrible experiments. The others will not be spared, obviously they will be simply pulverized into dust. So, there is a need for somebody to save humankind.
The Aliens have settled over Earth and are now in orbit. In response Earthlings quickly build an armed spaceship and equip an expedition to give battle. It becomes known that the alien energy is contained in crystals scattered all around the Arcadrome (their vehicle launching site). The only way to neutralize their hordes is to capture all crystals and to leave the enemy without energy. That is the last hope of humanity. The spaceship is cramped, and only one man can go in (may be bad since calculated in a hurry). And you have been selected as that one man. Your civilization is gazing up to you as their sole hope for survival.
"Out of everybody trying to save our planet Earth you are the selected one", said the President grimly at parting, his face grave with concern.