With the help of the reader, two detectives search for the letters of the alphabet.

As a nearly full-fledged member of the Agency, the all-female detective unit based in Miss Scrimshaw's Academy for Girls, Mary Quinn, disguised as a poor apprentice builder, must brave the sinister underworld of Victorian London in order to unmask a murderer.

Geronimo explores a haunted mansion populated by ghosly cats.

The reader is invited to solve the mystery of the television monster who is trying to close down the TV station.

When thirteen-year-old Logan and his family move into a run-down old house in rural Virginia, he discovers that a woman was murdered there and becomes involved with his neighbor Arthur in a dangerous investigation to try to uncover the killer.

Herculeah Jones gets involved in another dangerous mystery when she goes to visit old Mr. Shivers Hunt, resident of the forbidding Hunt House.

"Splat notices that his favorite wooden ducks keep going missing--can Secret Agent Splat solve the mystery?"--

Q (Quest) and Angela make it to the White House in Washington, D.C. to find that it is even harder to determine who are the "good" and "bad" guys than ever before.

When therapy dog Buddy attends the fourth grade sleepover in the school's library, he solves the mystery of the school ghost.

Moving on to her latest venture, Andi is excited when her newspaper for dogs becomes a big success, but when a group of evil dognappers use it to kidnap the pooches she knows and loves, Andi must do everything she can to catch the culprits and return all the dogs back to their rightful owners.