Four neighborhood friends, who call themselves by the nicknames Wizard, Skinny, Tubby, and Snitch, have their own private detective club.  Their club meets in a backyard clubhouse at Wizard and Snitch’s house, and they solve mysteries in their own neighborhood. The four boys have a rivalry with some of the neighborhood girls (including some of the boys’ sisters), and a couple of books in the series have boys vs. girls themes.

The four boys are:

Wizard – The leader, and the club is named after him, Wizard Private Eye. Wizard’s kitten’s name is Silent Sam.

Snitch – The youngest, Wizard’s little brother. He likes to yell a lot, and he loves his cat, Mildred, even though others think she’s a pest. However, Mildred later has kittens, and the other boys become cat lovers, too.

Skinny – A black boy, who is also skinny, as his nickname suggests. He has more of a knack for mechanics and technology than the other boys. Skinny’s kitten’s name is Funny.

Tubby – As described by his nickname. He’s one of those characters who is supposed to be comically obsessed with food (which is annoying). Tubby’s kitten’s name is Smarty.

Some of the books in the series also appear in collection editions like The Private Eyes Club Treasury and Three Great Mysteries.

The series is by Crosby Bonsall, who has also written other books. Her full name was Crosby Newell Bonsall, and some of her books were published under the name Crosby Newell.

Books in the Series:

The Case of the Hungry Stranger (1963)

Someone ate Mrs. Meech’s blueberry pie, and she asks the boys to investigate.

The Case of the Cat’s Meow (1965)

Snitch becomes concerned that someone might steal his beloved cat, Mildred. When Mildred suddenly disappears, he believes that someone actually has stolen her, but there is another explanation.

The Case of the Dumb Bells (1966)

The boys acquire some old telephones, which they decide to use in their clubhouse. However, after their installation, strange things start happening around the neighborhood, like doorbells ringing with no one there. What is going on? Is it a prank or something else?

The Case of the Scaredy Cats (1971)

The boys argue with some of the neighborhood girls about who gets to use the clubhouse. After a big snowball fight between them, one of the girls disappears. Can the boys find her?

The Case of the Double Cross (1980)

The neighborhood girls are once again tired of the boys not allowing them into their club or clubhouse. However, the boys may be forced to change their minds when a strange man leaves them with a coded message, and the boys need help from the girls.