Człowiek, Który Spadł Na Ziemię by Walter Tevis

An enigmatic alien named Thomas Jerome Newton arrives on Earth with a mission to save his drought-stricken home planet. Disguised as a human, he uses his advanced knowledge to amass a fortune through innovative inventions, hoping to build a spaceship for his return journey. However, as he becomes entangled in human society, he faces the challenges of loneliness, addiction, and the corrupting influence of power, ultimately questioning the cost of his mission and the nature of humanity itself.