This article contains plot spoilers for the 2017 series of Twin Peaks.
One night, Cooper visited Buella's residence and asked her if she had Darya and Ray Monroe "back there." The two of them emerged and agreed to go with him, bidding farewell to the two cousins sitting nearby.
Darya waited for him at a motel, clad in her underwear. As Cooper arrived, she was talking to Ray on the phone, who had just told her that she was going to have to kill Cooper in Ray's place, as he had just been arrested. She lied to him that she had been talking to Jack. He joined her on the bed and then revealed to her that had killed Jack two hours prior. She tried to escape his grasp, but he restrained her. He then played a tape of the conversation she just had with Ray.
Darya asked Cooper if he was going to kill her, and he said that he was. She tried to escape again, but he restrained her once more and punched her in the face. At his questioning, Darya confessed that she and Ray were being paid half a million dollars to kill him, but she didn't know for whom. She tried to plea for her life, swearing that she would not have followed through. He asked her if Ray got the information from Hastings' secretary or coordinates, but she did not know. He showed her an ace with a strange symbol on it, telling her that was what he wanted. Darya tried to escape again, but Cooper overpowered her and shot her in the head, muffling the sound with a pillow.