Horse Latitudes portrays Chris Wilson's descent into drug use, criminality, prostitution and prison. For the most part, the setting is the Mission district in San Francisco with flashbacks to Los Angeles, Dar es Salaam and other places pertinent to his past. His lifestory is hard hitting, depicting the horror of addiction through to shocking anecdotes about murder, prostitution, the extreme characters that inhabit the Mission, and his experiences of incarceration - from county jail to the San Quentin psychiatric isolation ward.