Ellery and his agent, Howard Biggers, travel to the estate of the wealthy and eccentric Spencer Lockridge. It seems as though Biggers wants to turn one of Ellery's books into a play and is trying to get Lockridge to provide the financial backing. All goes for naught when Lockridge disappears while wearing a Mad Hatter's costume from the Alice in Wonderland theme party he was throwing. Whodunit? Could it have been someone from New York or maybe even Dallas?
| Name | Type | Role | |
|---|---|---|---|
| Peter S. Fischer | Writer | ||
| Frederic Dannay | Writer | ||
| William Benedict | Guest Star | ||
| Julie Sommars | Guest Star | ||
| Jim Backus | Guest Star | ||
| Lew Brown | Guest Star | ||
| Rhonda Fleming | Guest Star | ||
| Edward Andrews | Guest Star | ||
| Olan Soule | Guest Star | ||
| Larry Hagman | Guest Star | ||
| Julius Harris | Guest Star | ||
| George Janek | Guest Star | ||
| Patricia Smith | Guest Star | ||
| Carmen Matthews | Guest Star | ||
| James Sheldon | Director |