The mystical culture and history of Atlantis is recounted by the author, who claimed to receive these insights from a mystical spirit known as Phylos the Tibetan during the 1880s.

Various descriptions of Atlantean society are given; we are told that they were technologically advanced, with sophisticated cultural mores and religious rites. Wireless communication, climate control, and the use of water to generate electrical power for - among other things - a high-speed rail network are described. Devices which resemble the television, and others which are voice-activated, are likewise discussed.

In relating his personal history, which involved travel upon planets Earth and Venus, Phylos highlights some important parallels between his ancient society and the 19th century North American culture in whom his host, the author, resided. Phylos considers his spirit form to be a final incarnation; his memories of the destruction of Atlantis leads to a foreboding element - such an event may repeat itself in the modern society, as its achievements in science and technology reach fantastical new heights.

For its unusual detail and astonishing contents, A Dweller on Two Planets has long been influential in New Age and occultist belief movements.