The Wife’s Doll

After the wife bought a doll, her behavior became increasingly abnormal, often locking herself away. The husband repeatedly caught her acting intimately with the doll and heard ambiguous sounds coming from the room. Suspecting that a living person was hidden inside the doll, he began installing surveillance cameras and investigating in secret. As the truth gradually surfaced, he discovered that his wife had an unusual relationship with his good brother—who turned out to be her first love. The two conspired to set a trap, attempting to usurp the husband's company and harm him. In the end, the husband saw through the conspiracy, laid out a plan in advance, and brought the pair who teamed up to scheme against him to justice.

Synopsis from DramaGo.