Wu Zetian has Crown Princess Liu and Consort Dou killed after Wu Zetian's trusted lady in waiting Wei Tuan'er, who hates Li Dan (the reason why she did so is lost to history), falsely accuses Li Dan's wife Crown Princess Liu and Consort Dou of using witchcraft in 693.

Li Dan, fearful that he is to be next, does not dare to speak of them.

When Wei further plans to falsely accuse Li Dan, however, someone else informs on her, and she is executed.

Wu Zetian nevertheless has Li Dan's sons demoted in their princely titles, and when the officials Pei Feigong and Fan Yunxian are accused of secretly meeting Li Dan, she executes Pei and Fan and further bars officials from meeting Li Dan.

There follow accusations that Li Dan is plotting treason, and under Wu Zetian's direction, Lai launches an investigation.

Lai arrests Li Dan's servants and tortures them—and the torture is such that many of them are ready to falsely implicate themselves and Li Dan.

One of Li Dan's servants, An Jinzang, however, proclaim Li Dan's innocence and cuts his own belly open to swear to that fact.

When Wu Zetian hears of what An did, she has doctors attend to An and barely saves his life, then orders Lai to end the investigation, thus saving Li Dan.