Robert Allan is the author of The Phenomenon: Under the Hidden Sky, published by Liminal House. He has spent the better part of a decade tracing the phenomenon across cultures, centuries, and declassified government archives.

The Phenomenon: Under the Hidden Sky is a UAP (Unidentified Anomalous Phenomena) investigation drawing on declassified government documents, military encounter reports, and congressional testimony, including David Grusch's 2023 testimony before Congress. It examines the major competing theoretical frameworks proposed to explain the phenomenon — including the extraterrestrial hypothesis and Jacques Vallée's control-system model — before presenting Allan's own synthesis, the Layered Phenomenon Model.

A lifelong student of the unexplained, Allan grew up in the Ohio Valley and lives outside Pittsburgh, Pennsylvania. The Phenomenon: Under the Hidden Sky is his debut.