The Complete Novels of Earl Derr Biggers: 11 Mystery Classics, Thrillers & Detective Stories (Illustrated): The House Without a Key, The Agony Column, The Chinese Parrot, Behind That Curtain, The Black Camel, Charlie Chan Carries On, Keeper of the Keys, Love Insurance, Inside the Lines, Fifty Candles…

Inside the Lines: A Tale of Espionage, Intrigue, and Romance in World War I

Behind That Curtain

The Black Camel

Fifty Candles (Serapis Classics)

The House Without a Key

The Chinese Parrot

Seven Keys to Baldpate

The Chinese Parrot

The Best Thriller Novels of Earl Derr Biggers

Seven Keys to Baldpate

The Agony Column (The Second Floor Mystery)

SEVEN KEYS TO BALDPATE (Mystery Classic): Mysterious Thriller in a Closed Mountain Hotel

The Chinese Parrot

Love Insurance

Seven Keys to Baldpate: Mysterious Thriller in a Closed Mountain Hotel

The Greatest Mysteries of Earl Derr Biggers – 11 Titles in One Volume (Illustrated Edition): Seven Keys to Baldpate, Inside the Lines, The Agony Column, Love Insurance & Fifty Candles (Including the Charlie Chan Series)

Seven Keys to Baldpate

The House Without a Key

Seven Keys to Baldpate: Mysterious Thriller in a Closed Mountain Hotel