The Green Girl — Jack Williamson

Love transcends. This doesn't hold truer than in this pulp classic by Jack Williamson.
Melvin Dane has been seeing a vision of a green girl since he was a child. Images of her came over the ether. Is she just fantasy? Or a reality that managed to cross time and space? And now, with the Earth under threat of extinction, will Melvin ever meet that girl of his dreams?

With an alien force trying to bring Earth back to the Ice Age, Melvin and his foster father, scientist Sam Walden, embarked on a heroic quest to save their world. Their adventures took them from their sleepy little cottage in the beaches of Florida to the unexplored and totally unexpected world beneath the ocean. There, Sam and Melvin find what they are looking for, and more. Sam meets the alien force trying to kill humanity, and Melvin meets the love of his life, the one girl he has been dreaming of since he was a child.

In their quest for redemption for the Earth they call home, both of them would find the love that would change their lives forever.