In Cape Town, a group of friends are having a barbecue. The day is disrupted when Ryan’s son goes missing. Taking place over one weekend, this sparks a series of incidents which puts a strain on Ryan, his friendships, and his marriage. Ryan's destructive actions while desperately searching for his son spark more arguments and unknown events from the past are revealed, while Ryan continues to find himself in difficult situations, despite his best intentions.
The Heart Is A Muscle is a humanist drama about generational healing and forgiveness, and a man learning that in order to be a better father, husband and friend, he must first learn to forgive himself.