An omnibus volume of two of Marion Zimmer Bradley's classic, long-unavailable Darkover novels, including the first Darkover novel ever written!

To Save a World includes The World Wreckers and the Planet Savers, plus the short story "The Waterfall."

The Planet Savers:

Originally published in Amazing Stories in December 1958, The Planet Savers was the very firs Darkover novel to see print. It was here readers were first introduced to the now legendary world of Cottman IV, at a time when the Terrans are desperately seeking a cure to a disease of epidemic proportions that threatens the lives of Terrans and Darkovans alike.
 
For every forty-eight years, Trailmen’s fever, a childhood illness among this native and venerable race, becomes pandemic, decimating the human population of this rustic planet. Now, one brave Terran doctor must join a Darkovan expedition into the wild mountainous terrain of the Trailmen in a desperate attempt to create a vaccine and eradicate this terrible plague once and for all.
 
The World Wreckers:

Planetary Investments Unlimited—that was the company’s official name, but unofficially it was known as Worldwreckers, Inc. For a fee, its agent would infiltrate any world unwilling to give up its independence, and do enough damage that the natives would be forced to allow Terran investors to step in and salvage their planet. And now, once again, its agents were at work.
 
In the 78 years since the planet Cottman IV—called Darkover by its natives—was rediscovered by the Terran Empire, all efforts to colonize and industrialize this exotic world had failed.
 
And the person in charge of Worldwreckers, Inc.—a centuries-old being who appeared to be a woman—had decided to take on this particular assignment herself. After all, she had special insight into this world, for long ago—lifetimes ago—she had called Darkover home….