Dr. Rich and his wife, Kathryn, attend a party celebrating their fifth wedding anniversary, but tension lingers between them due to Rich's growing romantic feelings for Kathryn's sister, Evelyn. Rich's deep dissatisfaction with his marriage becomes evident, and he secretly desires a future with Evelyn. Despite Dr. Hamilton, a family friend, trying to counsel him about patience and rekindling his marriage, Rich becomes frustrated when Kathryn explicitly refuses to grant him a divorce. The couple decides to take a trip to the mountains in hopes of revitalizing their relationship on the advice of Dr. Hamilton. Unfortunately, on their way there, an accident causes them both to return home.

After the accident, Rich's thoughts about escaping his marriage intensify. However, when Kathryn suddenly disappears unexpectedly under mysterious circumstances, Rich sees this as an opportunity to pursue Evelyn more freely. The police become involved in the search for Kathryn, but no trace of her is found. Dr. Hamilton grows suspicious of Rich's behavior and embarks on his own investigation. As Rich attempts to hide the truth and advance his own desires, he finds himself increasingly entangled in a web of deceit and guilt. A suspenseful atmosphere prevails as Rich's actions are brought into question, ultimately leading him to confront the consequences of his conflicts and desires.