In Garage Sale Mysteries: Murder In D Minor, Jennifer Shannon (played by Lori Loughlin) is a savvy garage sale shopper and amateur detective who stumbles upon a sinister mystery while bidding on a vintage self-playing piano at an estate auction. After winning the bid, Jennifer begins to research the piano's previous owner, Carl Deats, a wealthy philanthropist with a shady past.
As Jennifer delves deeper into Deats' history, she uncovers a web of secrets and lies, including a connection to a local nursing home where several mysterious deaths have occurred. With the help of her husband, Jason (played by Steve Bacic), and friend Dani (played by Sarah Strange), Jennifer sets out to uncover the truth behind the murders.
As Jennifer and her team dig deeper, they realize that the killer may be closer than they think, and they race against time to catch the culprit before they strike again. Along the way, Jennifer must navigate a web of deceit and suspicion to bring the killer to justice and uncover the truth about Carl Deats' dark past.