An 1850 Connecticut mill town becomes as real as today when 15-year-old Kate Calambra goes to bed in her family's newly acquired old house and wakes up there as the Irish mill girl Kate O'Hara. She finds six-day, 72-hour work weeks wearing and the child labor shocking, she worries with the others about Mother O'Hara's bad cough, and she tends her handsome older ""brother"" Patrick's leg wound after his run-in with Yankee Know-Nothings. But her major concern is to wrest Patrick from his tenacious girlfriend Nora and to convince him that she is not his sister but a visitor from the future and thus a legitimate object of the feelings he believes incestuous. (She succeeds, only to see Patrick marry Nora when the latter reports that she's pregnant.) Marzollo is not above staged melodrama, as when Mother O'Hara dies on the altar, clutching her hand-stitched altar cloth, as Know-Nothings burn down the Irish Catholic community's new church. And Kate's return to the present seems triggered chiefly by Marzollo's need to end the story. Kate's subsequent discovery from an old photo that Patrick and Nora are her great-great-grandparents ties the story up neatly but makes the incest angle kind of weird, as the contemporary Kate might say. Despite all this, readers will experience the 19th-century family life and mill conditions right along with Kate, and will share her involvement with Patrick to the end.