"When the Bough Breaks" is the 51st episode of Haven and the twelfth episode of the fourth season, airing on Syfy on 6 December 2013. The episode was the first half of a two-part story that concluded in "The Lighthouse." The title of the episode is a reference to the fifth line of the 18th Century nursery rhyme "Rock-a-bye Baby." It also shares its title with a 1985 Jonathan Kellerman novel, a 1988 Star Trek: the Next Generation episode, and a 2009 Castle episode.