during the phony fishing trip, removing all doubts about the existence of a plot.

Girard successfully secures Barnswell's written confession, which is lost when he's killed in a plane crash in Spain. Clark is taken captive when he reaches the secret base and held incommunicado. Exploiting their longtime friendship, Clark convinces the base's deputy commander Colonel Henderson of the actual intent of the impending "alert". Henderson frees Clark and leads an escape back to Washington but is abducted and confined in a military stockade.