Single-mom and police chief's daughter Kate Buckley is all about family. After she receives an urgent text from her younger sister Colleen, she puts her life on hold and rushes to her Irish-themed hometown of Shamrock, Massachusetts, where her family owns and operates a bed and breakfast. With her two daughters in tow, she's ready to fight if it means she can help her charming but hapless sibling.

When they arrive, Colleen claims it was all a misunderstanding. But everything changes in an Irish minute when Colleen's best friend, Deirdre, a dance show star, is found dead in the parish hall. With the discovery of a possible witness, a chilling motive, and a wee bit of incriminating evidence, Colleen quickly becomes a person of interest in Deirdre's murder. Convinced her sister isn't a killer, Kate is determined to clear Colleen's name.

As Kate investigates, Colleen takes charge of Shamrock's popular Irish dance show in honor of her late friend--with disastrous results. With the St. Patrick's Week festivities in full swing, Kate must catch the killer before the celebrations are ruined and her sister's Irish luck runs out.