Roots and wings

Summary: "When they aren't caring for patients, friends Evelyn, Joy, Anne, and Shirley quickly discover that Mercy Hospital, with its secret passageways and hidden historical treasures, is a place of intrigue, adventure, and amazing miracles. For more than a hundred and fifty years, it has been rumored that the building is under the protection of a guardian angel. But when its famous status goes missing in the middle of the night, everyone is scrambling to find out who stole it. The day after it disappears, a woman who has a striking resemblance to the statue shows up. Is she really hoping for a job at Mercy or is she there for another reason entirely - one that the four friends must discover together?"--Back cover.