In the quiet hills of rural Wales, two girls separated by a century are about to change each other's lives forever. When 14-year-old Amy arrives at a secluded farmhouse with her family for the spring holidays, she carries a silent weight -- the unresolved grief of losing her best friend, Suzy. As she seeks solace in an old upstairs room, Amy discovers a faded name and a cryptic inscription etched into the wall: BA - Sarah, 1904. What begins as a curious mystery soon draws Amy into a hidden past that speaks straight to her aching heart. Through old letters and a weathered notebook, Amy uncovers the story of Sarah, a spirited young girl swept up in the Welsh Revival -- a powerful spiritual movement that transformed lives and divided communities. As Amy reads about Sarah's courage, doubts, and faith, she begins to feel a stirring within herself -- one that mirrors Sarah's own journey of transformation. Told in alternating narratives, 'A Mystery in Spring' delicately weaves the lives of two girls -- one in mourning, one in awakening -- into a tale of spiritual renewal, personal healing, and the unseen threads that connect us across time. As Amy opens up about the guilt she carries over Suzy's death, she begins to understand the true meaning of grace, forgiveness, and being "born again." Eleanor Watkins crafts a tender and profound young adult novel about grief, faith, and the mysterious ways hope can bloom -- even in the most unexpected seasons.