Holt of the Secret Service

A secretary is found dead in a White House bathroom during an international crisis, and Detective Harlan Regis is in charge of the investigation....

Veteran Secret Service agent Frank Horrigan is a man haunted by his failure to save President Kennedy while serving protection detail in Dallas....

During an historic counter-terrorism summit in Spain, the President of the United States is struck down by an assassin's bullet. Eight strangers have...

After a treacherous attack, Secret Service agent Mike Banning is charged with attempting to assassinate President Trumbull. Chased by his own...

A famous scientist invents a humanoid robot (the titular "monster"), so a greedy rival scientist plans to steal it for use in his criminal plans. ...

An accomplished aviator sets out to locate treasure hidden by one of his ancestors. He encounters interference from various adversaries.

Kit Cardigan seeks the killer of his father...among other plot threads leading up to the famous historical incident.

Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.

Mystery and adventure, surrounding a stolen rubber harvest.

Jim Dorn endeavors to protect Jean McNain from a man she knows has committed a murder, Carter Snowden

Four flying G-Men protect America against enemy spies; one of the four assumes the identity of The Black Falcon, to befuddle the saboteurs even...

Pulp hero "The Spider" seeks to destroy all criminals. In this serialized adventure, he battles The Octopus, who intends to replace the government...