Lin Wanxing, a former financial auditor, discovers that the marital home whose mortgage she has been paying has been mortgaged without her knowledge. The signature on the mortgage contract is not hers, and the property deed has always been kept by her husband's elder sister. She hires a lawyer and uses lawful methods, including handwriting verification, legally requesting bank statements, and checking business registration records, to trace where the mortgage funds went. Despite repeated attempts to persuade and pressure her, she relies on her financial auditing expertise and insists on gathering evidence rationally. She eventually secures crucial evidence, and after submitting the relevant documents, the property's transfer registration is restricted, uncovering clues of a nominee ownership arrangement.