Earl Derr Biggers 
The Greatest Mysteries of Earl Derr Biggers – 11 Titles in One Volume (Illustrated Edition) [EPUB ebook] 
Charlie Chan Books, Seven Keys to Baldpate, Inside the Lines, The Agony Column…

‘Seven Keys to Baldpate’ – A young novelist William Magee travels to the Baldpate Mountain resort, seeking for solitude and inspiration for his greatest novel yet. Soon after he gets in, he finds out that he is not the only one there, for there are seven keys to the place and seven people with various stories of why they are there. ‘Love Insurance’ – The American branch of Lloyds’ insurers is specialized in unusual policies, but one day an impoverished Lord Harrowby showed up with the strangest claim of them all. He wants an insurance against his fiancée Cynthia Meyrick breaking off their engagement. ‘Inside the Lines’ – World War I has started, Britain has gone up against Germany, and few Americans are stranded at Gibraltar desperate to catch a boat back home. Spies are everywhere and Germans are plotting to blow up the English troop at Gibraltar. ‘The Agony Column’ (Second-Floor Mystery) – Geoffrey West is an American in London. Since arriving he has been fascinated by the Agony Column, a personal advertisements in newspapers. One morning he spots an American tourist girl reading the same section, decides to place an ad to catch her attention, and soon they start corresponding. ‘Fifty Candles’ – Young Winthrop is in love with Mary Wills and longs to marry her. His pursuit of her will lead him to a party in the home of a former employer, a millionaire with more enemies than friends. Millionaire is killed at the party, no one can be ruled out as a suspect, and some clues point to Winthrop. ‘Charlie Chan Series’ – Charlie is a Chinese American detective who lives on Hawaii and works for the Honolulu Police Department, but often travels around the world investigating mysteries and solving crimes.