When biochemist Professor H. Klauson develops a method to grant humanity immortality, strange forces seem determined to prevent his success. Each time he approaches the final experiment, his mind collapses into unconsciousness. His wife Lin begs him to abandon the research, sensing an otherworldly presence working against them. Despite support from the World Science Presidium's medical staff, no logical explanation emerges for his mysterious breakdowns.

As Klauson pushes forward with his life's work, he discovers his trusted assistant Larry Verrill harbors an extraordinary secret. Verrill is actually Varro, a fourth-dimensional being from humanity's evolutionary future who has traveled through time to prevent the professor's discovery. The revelation unfolds a cosmic paradox: if humans achieve immortality, they will cease evolving, preventing the emergence of the advanced beings who sent Varro back in time. In this intricate web of cause and effect spanning multiple dimensions, Klauson must confront the ultimate question of whether humanity's greatest gift might also be its greatest curse.