A Good Marriage (2014)

Bob and Darcy Anderson are happily married with two adult children. One evening while Bob is away on a business trip, Darcy goes into the garage to search for batteries. When rummaging through Bob’s things, she comes across pornographic magazines containing sadomasochistic images. Upon looking further, she finds a secret compartment behind the garage’s baseboard and inside is a small box containing ID cards of Marjorie Duvall, a victim of a serial killer known as “Beadie”. Horrified, Darcy looks up Beadie online and cross-checks Bob’s business records with the locations of the murders, finding that he was close to most of the crimes. She also sees a photograph of Duvall wearing earrings identical to the ones Bob recently gave her as an anniversary gift. Meanwhile, after spotting a young woman leaving a diner, Bob follows her in his car.

He then returns home to confront Darcy; he has deduced her discovery. He calmly explains his insanity to Darcy, recounting how he and a sadistic friend named Brian Delahanty, or “BD” (from which “Beadie” was derived), planned a school shooting as teenagers. However, Delahanty was hit by a car before they could carry it out, but Bob claims he had “infected” him with “certain ideas”, resulting in his homicidal urges. Bob claims that, after he started a family with Darcy, his murderous alter ego receded and he was not driven to kill again for several years. He asks Darcy to put the matter behind them for the sake of their children, and then falls asleep. The following morning, Darcy feigns an agreement to forget what she has discovered, on the condition that he does not kill again, and that he bury Duvall’s ID cards in the woods. Bob agrees.