In this last written adventure, the plot unfolds with an intriguing scenario. Wealthy and hospitible Dudley Ward gathers together Charlie Chan along with Ellens three later husbands to his large house on Lake Tahoe. After hearing his former wife, Ellen Landini, may have been pregnant when she left him, Dudley Ward is determined to find his son. There are four ex-husbands, including Ward, all of them angry with Landini, who is about to marry a fifth husband, also present, with his sister, at this bizarre gathering. Landini herself arrives on the scene to complete the madness, and is promptly murdered. Her servants, entourage and husbands all come under suspicion. Keeper of the Keys was the final book written by Earl Derr Biggers before his passing a year later.