Keeper of the Keys (1932) is the sixth and last mystery in the Charlie Chan series of Earl Derr Biggers; Biggers was planning on continuing the series, but died in 1933 before he could.

Once again, the setting of the novel is rural California, where Chan has been invited as a houseguest.

Once again, Chan is expected to solve the murder, which he does by understanding the key clues—the actions of a little dog named Trouble, two scarves, and two little boxes.

When he understands how the murder is committed, he learns the role of elderly house servant Ah Sing—the keeper of the keys.

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