“Sweet Revenge: A Hannah Swensen Mystery” (** out of four) was a half-hearted continuation of Hallmark’s “Murder She Baked” series about Hannah (Allison Sweeney) and Mike (Cameron Mathison) whose wedding plans and blissful relationship is severely interrupted by a murder at a local gym which raises everyone’s suspicions and security. Overly bland trifle never gathers much magic as a romantic comedy or a detective thriller and soon sputters. There are 28 novels in this series so you can be sure there will be more film adaptations to follow hopefully with more conviction and bite.