Walk-ins are souls that agree to exchange places with another soul. Other books have been written about walk-ins, but Walk-ins: The Cosmology of the Soul is the first book to provide details about the processes of a soul entering into a body, the various types of walk-ins such as soul infusions, soul braids, soul overlays, jumpers and soul layering; preparation of the energetic bodies prior to a walk-in entering, the different types of soul experiences soul origins and the nature of the soul. Walk-ins: The Cosmology of the Soul was published in 2020, by Sheila Seppi, with the assistance of 15 other walk-ins and 8 other people who provide their perspectives about walk-ins and the nature of souls. Many of those interviewed, remember their walk-in origins and hail from a number of star systems, star beings and dimensions such as Pleiadian, Sirian, Arcturian, Mantis, Lyran, Vega, Andromedan, other un-identified systems, the 7th-dimension and the 13th-dimension. Most would think of these beings as extraterrestrial.