Maryann Corenthal is a side character whose first and only known appearance was in [[.-] (one of the "Hidden" Videos.) Jeff approached Mrs. Corenthal during his trip south in an effort to reach her husband Dr. James Corenthal. At the time of Jeff's visit it was believed that Dr. Corenthal was dead, however Mrs. Corenthal at first seems to refer to him in the present tense. When Jeff mentions HABIT to her Mrs. Corenthal becomes quickly aggitated and demands that he leave her property. Because of these incidents it is believed that Mrs. Corenthal knows much more than she was willing to reveal. Her first name was revealed in the Corenthal Christmas letter.

It appears that at some point between Dr. Corenthal taking on Linnie as a patient and his decision to move East with her, Maryann and the Doctor separated. The second article from the Microfilm Collection released with One step forward, two steps back notes that she was flown in for the ceremony honoring her husband, and was very emotional about the reunion. The article describes her as "private."

The apartment number Maryann Corenthal currently resides in is 222.

Jeff and Vince realize in Dead end with a Pulse that Maryann may be able to provide more clues for them and they attempt to contact her. Jeff discovers that she has left the facility in which she was living, but the person helping Jeff suggests that she may have gone to NJ where she owns several properties that she was planning to rehabilitate. Jeff and Vince make the connection that she may be the owner of the property at Baldpate, and plan a visit. Unfortunately Jeff was kidnapped by HABIT before they were able to make that visit, but Vince went alone (documented in the video The property) and found Lady of the Light.pdf, a letter written by Maryann to her husband, and left at Baldpate. In the letter she details her actions after Corenthal's disappearance, and her decision to follow a protocol that he left behind and then go into hiding.