While working on a mysterious case involving disappearing eggs and a fiddle-playing fox named Frankie, Hank the Cowdog falls for Miss Beulah, the beautiful collie.
Despite warnings from a stranger, Nancy sets out for France to search for a flight of 99 steps which may help solve the mystery of a weird dream and a possible case of blackmail.
Fenton Rumplemayer discovers a fossilized dinosaur nest at his father's archaeological dig outside Morgan, Wyoming, but has to solve the mystery of why the dinosaur's remains are much too large for the eggs that were laid.
When Fenton Rumplemayer's best friend Max comes to visit him in Wyoming, he doesn't seem interested in the puzzling dinosaur remains or the town Halloween party.
When Fenton Rumplemayer's father goes to Hollywood for a week as a technical consultant on a dinosaur film, Fenton accompanies him and discovers strange mistakes and accidents plaguing the movie studio.
A professor with a reputation for being unafraid of ghosts moves with his family into a house that is supposed to be haunted but his children find the neighbors more mysterious than the house.