Having enough of a life investing money and brokering deals, John Smith retires to a quiet suburb in which he hopes nothing particularly interesting ever happens and where he can be left at peace with his philosophical musings. However, when the movers vacate the house across the cul de sac, leaving behind the requisite odds, ends, and family, John finds his retirement and solitude upset by Victor and Tristan, the bookish son and fanciful daughter of the staid Mr. and Mrs. Ratling. From his first encounter with the pair and their strange views, John realizes that something unusual has come into his life. Victor and Tristan follows the pragmatic John Smith through his reality-expanding journey from the mundane into the fantastic. Travelling from the hills near his home to the plains of a distant world with Tristan, Victor, the frank Mrs. Grummings, the irreverent Iridan, the enigmatic Cassandra, and the alchemical android Janus, John comes to terms with the existence of magic, alchemy, alternate realities, and even the possibility of eternal life. However, the strange, once encountered, can never be shut neatly away: all who embrace the improbable are forever changed. Can John, Victor, and most importantly, Tristan retain their own ideals and identities when encountering people and events who defy the simple monikers of "good" and "evil"?