What Keeps You Alive

Jackie and Jules, a young married couple, are celebrating their first anniversary at a remote cabin belonging to Jackie's family. Jules becomes suspicious when Jackie's childhood friend Sarah visits and addresses Jackie as "Megan". Jackie explains that she changed her name because it suits her better. Jackie gives Jules a locket containing a photo of them together, and they are seemingly reconciled.

Still concerned, Jules visits Sarah and her husband Daniel, who live across the lake. There, she learns that Jenny, a mutual friend of Sarah and Jackie's, drowned in the lake when they were young. Later, when questioned, Jackie claims that she never mentioned Jenny because she believed the accident was her fault, although the police had cleared her of any wrongdoing. Jules embraces her wife, consoling her. Moments later, while admiring the view of the wilderness, Jackie shoves Jules off the edge of a cliff.

Jackie returns to the cabin, practicing the tearful phone call she's going to make to the police when reporting Jules' death. However, Jules is still alive. When Jackie returns to the scene and discovers that Jules is no longer there, she searches the forest for her, sobbing and begging Jules for forgiveness. Jules, hiding nearby, is tempted to show herself until Jackie, unaware she's being watched, reveals her concern is an act. Jules flees, makes it to the house, and tends to her injuries. She then makes it halfway across the lake on a boat before Jackie catches up to her. Daniel sees the pair and, despite Jackie's threats, Jules arranges for them to come for dinner that evening.

Jackie reveals that she never loved Jules and intends to murder her to cash in on her life insurance policy. Sarah is suspicious of Jackie. Having threatened to kill both Sarah and Daniel, Jackie forces Jules to pretend everything is normal but catches Jules trying to get help from Sarah. She slits Daniel's throat outside, chases Sarah upstairs and fatally stabs her numerous times after confessing to Jenny's murder. Jackie forces Jules to help her dispose of the bodies. When asked how she became this way, Jackie reveals that she has simply always been devoid of sentiments or a conscience, saying it was "nature, not nurture". Jules peeks behind the stuffed head of a bear that Jackie supposedly killed as a child, and discovers a box containing necklaces that Jackie had given to her previous wives, confirming the situation happened several times.

Jackie drives Jules back to the cliff’s edge, intending to push her off again, but Jules manages to escape by stabbing her with a tranquilizer dart. Jules flees in the car, but returns to confront Jackie but finds her missing. Jules returns to the cabin and the two fight and Jackie knocks Jules out, and throws her over the same cliff as earlier. Confident that Jules is now dead, she calls the police. Jackie (who is diabetic), then injects herself with insulin but starts to feel woozy. She discovers through a video Jules had made before their confrontation that the insulin is replaced with hydrogen peroxide. The peroxide causes blood clots in Jackie's system, and after wandering in the woods, she collapses and dies of a stroke.

Back at the bottom of the cliff, Jules takes a sharp intake of breath and the film ends with flashbacks of the couple.

• Hannah Emily Anderson as Jackie / Megan
  • Charlotte Lindsay Marron as Young Jackie
• Brittany Allen as Jules
• Martha MacIsaac as Sarah
• Joey Klein as Daniel

In the early stages of the film's development, the main characters were a husband and wife (rather than a same-sex couple).^[1] Filming took place in Muskoka, Ontario.^[2]

Allen composed the film's score, earning her first such credit.^[3]

What Keeps You Alive had its world premiere at the SXSW Film Festival on March 10, 2018.^[4] Since then, the film has also screened at Inside Out, the Sydney Film Festival, Cinepocalypse, and Popcorn Frights, as well as other festivals.^[5][6][7][8]

IFC Midnight acquired the film for distribution in the United States.^[9] The film opened in Los Angeles and New York on August 24, 2018. It became available through video on demand the same day.^[10]