While the preceding nine volumes focused primarily on the secret US Air Force mission ("Operation Trojan Horse") that sent two "timenauts" to Judea in 30 A.D., El Día del Relámpago shifts focus to the immediate aftermath of the mission’s conclusion.

: Moving away from the purely historical and theological exploration of the previous books, this volume leans heavily into the thriller genre. It explores the dark underbelly of the mission's logistics, including the potential betrayal by General Curtiss and the shadowy project known as "Rayo Negro" (Black Lightning).

: The novel covers 101 frantic days following the protagonist's return to 1973. It addresses long-standing questions regarding the fate of the "Cradle" (the time-travel module) and the survival of secondary characters like Eliseo.

El día del relámpago (Biblioteca J. J. Benítez) (Spanish Edition)