William Olaf Stapledon - known as Olaf Stapledon - was a British philosopher and author of several influential works of science fiction. Stapledon’s writings directly influenced C.S. Lewis, John Maynard Smith, Arthur C. Clarke, Bertrand Russell, and indirectly influenced many others.

“Olaf Stapledon was one of the most creative thinkers of our time. His influence on philosophy and science fiction is incalculable.” - Greg Bear

Sirius is Thomas Trelone's great experiment - a huge, handsome dog with the brain and intelligence of a human being. Raised and educated in Trelone's own family, Sirius is a truly remarkable and gifted creature. His relationship with the Trelones, particularly with Thomas’s daughter, is deep and close, and his inquiring mind ranges across the spectrum of human knowledge and experience. But Sirius isn't human and the conflicts and inner turmoil that torture him cannot be resolved.