Before I read this book, I was unfamiliar with Michael Kube-McDowell; I had even read (and enjoyed) some of his short stories without knowing who he was. I didn't get too far into this novel, though, before I realized that I had missed one of the more under-appreciated talents in science fiction. In it, Walter Endicott, a businessman in 1966, discovers a gateway to a parallel Earth where he is a United States senator. Replacing his counterpart, he shares the knowledge about the gateway (part of a network connecting several alternate Earths) with a government desperate to gain an advantage in a Cold War struggle that the U.S. is losing to the Soviet Union. From this premise, Kube-McDowell builds a story around Endicott, the president, and a "runner" in an unhappy marriage, one that deftly mixes Cold War tensions with science fiction dimension-hopping. It's a work of alternate history that for its detailed plot and sophisticated yet relatable characters, stands head and shoulders above the others of its type.