What I believe is known as a locked room mystery, on an island.

The title is a reference to a "locked room mystery", a popular form of early detective fiction.

It is a locked room mystery of the subtype known as an "impossible crime".

This novel is a mystery of the type known as a locked room mystery.

The plot has the form of a locked room mystery.

Locked room mysteries are good clean fun, but I never heard of one happening in real life.

It is also the first locked room mystery in detective fiction.

The novel is a locked room mystery, which takes place at a wizards' convention.

Bel and the Dragon is perhaps the earliest example of a locked room mystery.

This version has been cited as an ancestor of the "locked room mystery".