Wandl the Invader (version 2)

Wandl the Invader, written by Ray Cummings, is a science fiction novel published in 1932. The story unfolds as humanity engages in interplanetary commerce with Mars and discovers a mysterious tenth planet, Wandl, which disrupts the solar system's balance. This planet is not barren but inhabited by intelligent beings and creatures, posing a significant threat to Earth and Mars. The novel is notable for its imaginative exploration of interstellar trade and conflict, serving as a sequel to Cummings' earlier work, Brigands of the Moon.