Any official departure of Judge Dee from the court compound (which also includes his private living quarters) is done with fanfare, accompanied by a large retinue of constables and officials. This approach is sometimes useful - especially when suspects are to be overawed and intimidated, or recalcitrant local officials intimidated into fully cooperating with an investigation. Sometimes, however, Judge Dee finds it expedient to go out incognito and carry out an investigation in disguise. He carries off very well the disguise of an itinerant physician; as Van Gulik points out, knowledge of medicine was expected of Chinese literati. Conversely, Judge Dee is less successful in passing himself off as a merchant, a member of a completely different social class; an observant merchant quickly unmasks him as what he is, a member of the Literati elite. Fortunately, it turns out that this observant merchant is not the wanted criminal; on the contrary, he is an honest merchant, with his own accounts to settle with the criminal, who become a very valuable ally.