Spry septuagenarian Sister Mary Helen and her sidekick Sister Eileen continue to make murder their habit in their eighth charming adventure. When the holiday festivities are dampened by the murder of a pastor of the nearby St. Agatha's Church on St. Patrick's Day, the Sisters of Mount St. Francis College are confronted with a host of underhanded goings-on to investigate. To start with, someone had been embezzling funds from the church. Its pastor, the late Monsignor Joseph Higgins, seems to have been a man with many enemies. Six prominent members of the congregation all seem to have had the motive and the opportunity to poison the Monsignor, as did his disagreeable housekeeper. Merry mayhem ensues as the nosy pair of nuns delve into the much-disliked Monsignor's dirty past to uncover the killer.