Uninvited Guest

Four people are gathering for dinner. For one of them, it will be the last. Matthew is the perfect husband. Titus is the perfect son. Charlie is the perfect illusion. Rachel is the perfect stranger. A minute ago, everything seemed fine, but now there is a corpse at the table, and the uninvited guest has a bloody knife in her hands. It seems that everything is obvious. Especially since the criminal confessed herself. But what if she had other reasons to confess? What if the killer is not her, but someone else?