Gang War is a film set in London in the early 1960s that follows the life of Clyde (Jack Pickford), a saxophone player. He meets a beautiful young woman named Flowers (Olive Borden) with whom he falls in love. However, a local gang leader named Blackjack (Eddie Gribbon) is also in love with her. Blackjack ends up winning the heart of Flowers, and he marries her but does not consummate the marriage. War erupts between Blackjack's gang and a neighboring gang leaving several dead including members of each leader's family. A London inspector steps onto the scene trying to stop the mob violence, but to little avail. In fact, the detective begins falling in love with one of the gang leader's daughters. Will the violence ever come to an end, and will Flowers stay with Blackjack? Bert Glennon directs this crime drama packed with loads of action and killer suspense.