The Three Investigators mysteries have been a favorite among preteen readers since its original publication in the 1960’s. The popularity of the series isn’t limited to kids lucky enough to snag a paperback copy — competition for owning these increasingly hard-to-find novels includes many of those original readers, book collectors, and an international following devoted to the adventures of young Jupiter, Pete, and Bob.

Editions of the original series — featuring Alfred Hitchock’s name and insignia — are a coveted prize indeed. Published in the 1960’s and 70’s, these mysteries include thrilling titles such as “Terror Castle”, “Whispering Mummy”, and “Green Ghost”. Both hardbacks and softcovers were published in various designs, each including the trademark “introduction” by the investigators’ sponsor Alfred Hitchcock.

Following Hitchcock’s death, the series was retitled as simply “The Three Investigators” with Hitchcock’s name removed from any future titles. A fictional mystery writer named Hector Sebastian picked up where Hitchcock left off as the sponsor and guide for the boys’ adventures. The later titles included favorites like “Scar-Faced Beggar” and “Cranky Collector”. Hitchcock’s trademark symbol was removed from the editions and replaced with the new insignia, a keyhole.

While multiple volumes were published of the early titles, the series underwent a transformation after the Hitchcock estate demanded additional fees for the use of his name on the original volumes. The dispute ended with the removal of Hitchcock’s name and insignia from all future publications — including the original Hitchcock volumes. The books were rewritten slightly to remove Hitchcock’s name and any reference to him, with Hector Sebastian taking his place in the editions published during the 1980’s until the series publication dwindled.

The Hitchcock volumes are especially coveted by fans and collectors for their nostalgia and the growing rarity of these editions. While many keyhole editions exist of the early novels, many prefer to hold out for a Hitchcock insignia — others still more for the original hardback covers that defined the 60’s editions of the series.

The Three Investigators following isn’t limited to the United States: Germany, Great Britain, and other countries have developed intense followings for the three young detectives. Germany’s Three Investigator cannon includes a long list of additional novels written exclusively for its market and not published in the U.S. European plans to make a movie about the boys’ adventures is further proof of their glowing international reception.

As collectors scour flea markets and compete on Ebay for the series, still others dust off their old copies and plunge into the exciting youth adventures yet again.