In her celebrated science fiction novels, “The Sparrow” and “Children of God,” Mary Doria Russell explored the wonders of humanity’s first contact with alien life. But it’s her last contact with Random House that remains a mystery to her.

Just as her new novel, “Doc,” was being released in 2011, she got word that her publisher was not interested in any more books from her. She had been with Random House since 1996 and published five novels with the New York house. During that time, she had won an Arthur C. Clarke Award and an American Library Association Readers Choice Award. Entertainment Weekly had chosen “The Sparrow” as one of the 10 best books of year.

But that didn’t matter. Random House was done with her.

“There was no indication that was going to happen,” she said at the Howard County Library Gala on Feb. 23. “It was like having your husband throw you a 25th wedding anniversary party, and then serve you with divorce papers at dessert.”

Stunned and confused, she remained quiet about Random House’s decision because she had to begin her book tour for “Doc,” a western about John Henry Holliday and Wyatt Earp. Ironically, given her publisher’s termination of their relationship, the novel received very positive reviews and was chosen as one of The Washington Post’s top five novels of 2011.

“It took me about three months after that till I could breathe right. I’d been so happy there. The sales people were great with me,” she said. “But there was a lot churning with the editors. I’d had nine editors for my five novels.”

Russell, who holds a Ph.D in biological anthropology, speculated that her experience with Random House may be symptomatic of the industry’s changing attitudes. Debut novelists still get picked up, but midlist authors are under ever increasing pressure to produce blockbusters — or ride away into the sunset.

Fortunately for Russell, a new sheriff strode into town. In 2012, Ecco, a division of HarperCollins, bought the planned sequel to “Doc.” Russell said she expects her new novel — tentatively called “Epitaph” — to be published in late 2014. It follows the characters in “Doc” to the gunfight at the OK Corral. (Clearly, Ecco knows what it’s doing. The imprint also published the other great Western of 2011, “The Sisters Brothers,” by Canadian-born Patrick deWitt.)

And the good news keeps coming for Russell: Ron Howard and Akiva Goldsman are producing a pilot episode for an HBO series based on “Doc” and “Epitaph.” And AMC recently bought an option to make a series based on “The Sparrow” and “Children of God.”

The old adage still holds: When you fall off the horse, you’ve got to get right back on. Mary Doria Russell is still very much in the saddle.