It's fall in North Harbor, Maine, where Sarah owns a charming secondhand shop and sells lovingly refurbished items of all kinds. The shop is always bustling--and not just because a quirky team of senior-citizen detectives works out of it and manages to get in even more trouble than Sarah's rough-and-tumble rescue cat, Elvis.
A cold case heats up when young Mallory Pearson appears at the shop. Mallory's father is in prison for negligence after her stepmother's mysterious death, but Mallory believes he is innocent and asks the in-house detectives to take on the case. With Sarah and Elvis lending a paw, the detectives decide to try to give Mallory's father a second chance of his own.