July, 2090: the Callahan Clean Earth Protocols have been active for fifteen years, but still the planet is in peril.

Stone Callahan has dreams of poisoned rivers, dying wildlife, and a crumbling environment pushing humanity to the brink. Finite resources can only last so long, and there are large numbers of people bringing the horizon closer and closer. Stone has enemies everywhere. International corporations, government agencies both foreign and domestic, and military leaders around the globe all want him dead. They'll stop at nothing to protect their profits, building vast bank accounts atop mountains of corpses.

Enjoy all six installments in the Adventures of Stone Callahan omnibus edition, a thrilling eco-adventure of epic proportions! Lace up your boots, don your hat, and join Stone Callahan on his global journey to preserve the only planet humanity has ever called home.

R.F. Walden writes cli-fi, or climate fiction, about the complex interactions of mankind and the environment-interactions that often come paired with catastrophic consequences when the wrong choices are made. Fans of Barbara Kingsolver, Kim Stanley Robinson, Margaret Atwood, and anyone with a strong desire to see planet Earth survive are sure to love Stone Callahan and all the other cli-fi adventures from R.F. Walden!