Harvey's marvelous monkey mystery.

Alfred Hitchcock and the three investigators in The mystery of the headless horse / text by William Arden [i.e. D. Lynds] ; illustrated by Jack Hearne ; based on characters created by Robert Arthur.

Encyclopedia Brown and the case of the midnight visitor.

Alfred Hitchcock and the three investigators in The mystery of the dancing devil / text by William Arden [i.e. D. Lynds] ; illustrated by Jack Hearne ; based on characters created by Robert Arthur.

The case of the elevator duck / by Polly Berrien Berends ; illustrated by Diane Allison.

Alfred Hitchcock and the three investigators in The mystery of the shrinking house / text by William Arden ; illustrated by Jack Hearne ; based on characters created by Robert Arthur.

Alfred Hitchcock and the three investigators in The secret of Skeleton Island / text by Robert Arthur ; illustrated by Harry Kane.

The mystery of the screaming clock.

Houseboat mystery / illustrated by David Cunningham.