In Garage Sale Mysteries: The Mask Murder, Jennifer Shannon (played by Lori Loughlin) is an expert in antiques and garage sales who often finds herself solving crimes. When she purchases a storage locker at auction, she discovers a dead body inside. As she investigates the mystery, she learns that the victim was a former student of a famous art teacher who had a reputation for pushing her students too hard. She also finds a mask that matches one that the deceased woman had been wearing in a photo, leading her to believe that the killer may have been someone from the art world. With the help of her friend and business partner, Dani (played by Sarah Strange), Jennifer begins to uncover a tangled web of relationships and secrets, putting herself in danger as she gets closer to the truth. As the killer closes in, Jennifer must use her wits and her knowledge of antiques to solve the case before it's too late.