Visitor is a full-motion video (FMV) detective suspense game. The game tells a story that on a winter night in 2017, a murder case happened in a residential building, a prostitute Shasha died in her own home. Players, playing the role of police, should make a painstaking investigation among a great number of testimonies and evidences, to restore each detail of the whole murder case step by step, so as to find the real murderer.