"Mission" by John Hollis Mason is a science fiction narrative written during the early 1940s. The story explores themes of survival, colonization, and the clash of civilizations as it delves into the encounters between alien life forms and primitive Earth dwellers. The text is set against the backdrop of an impending extinction faced by the Martians, who seek a new home on Earth. The book follows Krai, a Martian tasked with assessing Earth's viability for settlement amid his planet's dwindling resources. Upon landing, he discovers a village of primitive tree-dwellers and uses his advanced technology to destroy their homes, believing there is no intelligent life there. However, one of the tree-dwellers, returning from a hunt, seeks revenge after witnessing the destruction of his community. In a fateful encounter, the tree-dweller manages to kill Krai with a thrown stone, showcasing the unexpected consequences of the alien's ruthless mission. The narrative culminates in a confrontation between the two species, highlighting the theme of revenge and survival against a backdrop of technological disparity. (This is an automatically generated summary.)