Dr. Reardon is an ambitious parapsychologist hell-bent on proving ghosts exist in Rose Red, willing to do anything – sacrifice anyone – to do it. Her main focus is on the young girl, Annie, making her particularly evil.
She doesn’t kill anyone directly, but she brought these folks here to wake the house up, and is essentially responsible for their deaths.
Joyce is very driven by her career and objective to prove ghosts exist. She only becomes more driven when her tenure is taken away.
Joyce frantically tries to save her equipment as the crumbles around her. She finally uses some sense and tries to leave, but the house won’t let her. The ghosts descend upon her, presumably killing her and making her part of the house. The parting shot is Joyce in the tower as a ghost (alongside the skeletons of Ellen and Sukeena).