Robert A. Heinlein (1907-1988) is widely acknowledged to be the most important and influential American science fiction author of the twentieth century. He won science fiction's Hugo Award for Best Novel four times, and in addition, three of his novels were given Retrospective Hugos fifty years after publication. He won Science Fiction Writers of America's first Grand Master Award for his lifetime achievement. Born in Butler, Missouri, Heinlein graduated from the United States Naval Academy and served as an officer in the navy for five years. He started writing to help pay off his mortgage, and his first story was published in Astounding Science-Fiction magazine in 1939. In 1947, he published a story in The Saturday Evening Post, making him the first science-fiction writer to break into the mainstream market. Long involved in politics, Heinlein was deeply affected by events such as the bombing of Hiroshima and Nagasaki and the Cold War, and his fiction tended to convey strong social and political messages. His many influential novels include Starship Troopers, Stranger in a Strange Land, The Moon Is a Harsh Mistress, and Time Enough for Love.

Spider Robinson, winner of three Hugos and a Nebula, was born in the Bronx and raised on Long Island, and has been a Canadian resident for 30 years. Holder of a bachelor's degree in English from the State University of New York, he worked as a folksinger and journalist before publishing his first story in Analog in 1973. He now lives on an island outside Vancouver, B.C., where he raises and exhibits hopes.

Over ten of Robinson's books are set in Callahan's Place (including Callahan's Crosstime Saloon and Callahan's Key), a fabulous tavern founded by a time traveler, where puns flow as freely as beer, and smell far worse. Robinson has contributed a regular editorial column, "Future Tense," to Canada's national newspaper, The Globe & Mail, since 1995. In 2000, he released Belaboring the Obvious, a CD of original music with the legendary Amos Garrett ("Midnight at the Oasis") on lead guitar, and in 2001 he was a celebrity judge at the Cannabis Cup in Amsterdam.