A well-crafted time-travel novel. Tam, 12, steps through the fireplace of a ruined Yorkshire farmhouse, along with a bag lady and her friendly dog, and into Sam Nutter's lively farmyard during WW II. In spite of the strangeness of it all, he's soon laughing at May, 8, who comes careening around the corner astride a large spotted pig. Tam and May form an instant alliance; her troubled past and his sudden displacement in time make them both not quite right in others' eyes. It's an important, life-changing friendship. When Tam returns to his own time, he faces difficult truths about May, and finds it in himself to remain a loyal friend. A convincing story that plays by all the rules; no small slip in detail interrupts the suspension of disbelief. Burgess's seamless tale skillfully uses the bag lady and her dog as links between past and present. Terrific characters (especially Sam, the gruff old farmer with a heart of gold), a realistic, beautifully evoked setting, and the colorful Yorkshire dialect brings this story to life. Thoroughly satisfying.