The Emperors Pearl is a gong'an detective novel written by Robert van Gulik and set in Imperial China (roughly speaking the Tang dynasty).

It is a fiction based on the real character of Judge Dee (Ti Jen-chieh or Di Renjie), a magistrate and statesman of the Tang court, who lived roughly 630–700.

Judge Dee, magistrate of Poo-yang, a flourishing walled city on the Grand Canal, is attending the Dragon Boat races accompanied by his three ladies aboard his own official barge.

He is mildly annoyed by the intrusions of assorted callers and the loss of a blank domino (he and his ladies are keen players).

He is more than annoyed when the sad, sudden death of a young student crewing one of the boats turns out to be deliberate murder.