 Daphne finds an engagement ring in Martin s drawer. Appalled at the prospect of having Sherry for a stepmother, Niles hires a private detective to check out her background. Furious, Frasier orders the investigation called off, but not before the detective reports that Sherry has no less than five ex-husbands. Worried that she is unable to maintain a relationship, the boys try to drop hints to Martin. Martin angrily informs them that he s known about her other marriages from the beginning. It turns out, though, that Martin has decided to break up with her because he knows she isn t interested in marrying again.