The Halloween Tree by Ray Bradbury
Trade paperback format. Highly recommended!
"A fast-moving, eerie…tale set on Halloween night. Eight costumed boys running to meet their friend Pipkin at the haunted house outside town encounter instead the huge and cadaverous Mr. Moundshroud. As Pipkin scrambles to join them, he is swept away by a dark Something, and Moundshroud leads the boys on the tail of a kite through time and space to search the past for their friend and the meaning of Halloween. After witnessing a funeral procession in ancient Egypt, cavemen discovering fire, Druid rites, the persecution of witches in the Dark Ages, and the gargoyles of Notre Dame, they catch up with the elusive Pipkin in the catacombs of Mexico, where each boy gives one year from the end of his life to save Pipkin’s. Enhanced by appropriately haunting black-and-white drawings."–Booklist