This photoplay is based on the theory that Latin nations might combine their interests and rule the universe. Representatives assemble in Washington to formulate and sign a compact which, if negotiated on American soil, would violate the neutrality of this country. There comes from Europe to assist in perfecting the arrangements a clever diplomatic spy. Her presence here attracts governmental attention and through following this elusive young woman the plotters are finally apprehended, and their purpose thwarted. To this end the most skillful operative in the United States Secret Service is entrusted with the work of finding out why "Elusive Isabel" is here and to foil the plotters in their intrigue. To make matters more interesting the Secret Service agent is in love with Isabel and while he follows her through various sensational episodes, he is greatly disturbed in realizing that the woman he loves is engaged in such unfriendly actions toward this government. The purpose of the Secret Service to prevent the compact being signed on American soil provides the excitement. Isabel's partially demented brother, crazed by inventive research concerns himself in the plan and uses his mechanical and electrical experiments in forwarding the propaganda.