It is midnight in the dark land of Ethan Frome, and John Gardner has just walked into his house. He sits down immediately at a typewriter on the cluttered kitchen table. As he works, the compulsive 43-year-old author of such unusual and disparate novels as Grendel and October Light transports himself into another world. "I flick a switch and chairs turn into bears and gremlins," he says, brushing back the long hair that mysteriously turned white when he was only 18. "I like to hunt in weird caves and woods to make characters who brood over twisty ideas."

Gardner will not talk about the book in progress—his new "monster," as he calls it. "It's bad luck," he says. "As if you've betrayed it." Considering the speed at which he writes, Gardnerphiles will not have to wait long to find out. Since 1966 his outpouring has included seven novels, a book-length poem, Jason and Medeia, five children's books, several librettos, two translations of Middle English poetry, critiques of Old English poetry and medieval mystery plays, 50 poems and a biography of Chaucer.

Gardner's latest novel, October Light, is his greatest commercial success. It won the National Book Critics Circle fiction award for 1976 and is selling over a thousand copies a week. In it Gardner explores the relationship between an old brother and sister who live in crotchety combat on a Vermont farm.

Like them, Gardner isolates himself to write. "I need to be solitary," he explains. "An artist cuts off part of the world to explore it." Seven months ago Gardner left his wife of 23 years, Joan, and their two children, Joel, 17, and Lucy, 15. He moved from Old Bennington, Vt. to Cambridge, N.Y., 19 miles away.

He lives alone in a tiny rented house filled with volumes on Beowulf, books by Isaac Asimov and Sylvia Plath, prized musical instruments and pots and pans. Mozart or Gershwin pours from the stereo. "Music is the one thing I'd die without," he says. Gardner himself plays French horn, guitar, trumpet and banjo.

He has passed his interests on to the children. Joel plays the French horn and Lucy cello in an all New England orchestra. She is also the author of two novels and 20 stories. Joan, 43, who helped Gardner write the novel-within-a-novel in October Light is, according to him, a "sometime composer with an amazing ear for original melody—but lazy." Joan says, "His imagination is funny lately." The Gardners, who are distant cousins, have known each other since the age of 2. He dedicated the Chaucer book to his wife and children and visits them once or twice a week.

Gardner grew up on a dairy farm in Batavia, N.Y. His mother taught high school and his father, an itinerant preacher, composed sermons while driving a tractor. John went to Washington University in St. Louis to be a chemist but graduated in 1954 with a major in creative writing. "You do what is valued. Writing was valued in my family." By 1958 he had earned a Ph.D. from University of Iowa. Since then Gardner has taught at Oberlin, Northwestern and Bennington, and is still at it. Three days a week he commutes in a battered Plymouth between the campuses of Skidmore in New York and Williams in Massachusetts. ("Don't tell me," he admonishes one class in creative writing. "Make me feel it. In the beginning I don't care if you write like pigs, as long as it's all there.") Gardner earns about $50,000 a year from writing and teaching, but Joan considers his tearing from state to state "maniacal."

"My biggest problem," he says, "is that people catch me, and I begin to get social. The only way to write and teach is to keep going away."