Alien Pace's choice

You Louisians have always lived on the planet Lewis in the solar system, in harmony and friendship and with a developed civilisation. The Louisians have the ability to give life force to another object if they can voluntarily sacrifice themselves. Your people were simple until one day your planet was invaded by the Earthlings, who captured the Louisians in large numbers because of their life-giving powers. 

You Louisians have been trying to fight back.The Louisians have been going among the people to select Louisians to go to Earth in order to fight back, but the exact mission has never been revealed, and dozens have been sent to Earth who are said to have died and are unaccounted for.