Long reputedly ghost-wrote two, possibly three, of the Ellery Queen Junior novels (see Ellery Queen (house name) (mentioned in correspondence with August Derleth) but unfortunately did not identify the three titles. It has been speculated by researchers that the two are: "The Golden Eagle Mystery" (1942) and "The Green Turtle Mystery" (1944). The third one may have been the fugitive "The Mystery of the Golden Butterfly", which was apparently never published. (This volume is mentioned as Long's on the rear panel of" The Horror from the Hills" and on the rear flap of" The Rim of the Unknown").