Bonny Starr and the Riddles of Time — Gwen Grant

When Bonny inadvertently finds the object which the stranger so desperately wants, she is drawn into a mysterious and terrifying struggle between the Dazzling Clown and the kindly Black Monk. Suddenly, the whole fate of Time and Eternity, good and evil, lies in the hands of Bonny Starr.

Bonny was suddenly wide awake.

With a catch of fear in her throat, she saw the same white shadow that had followed her in the graveyard begin to appear.
“Who are you?” she cried. “What do you want?” The dazzling white figure smiled, a narrow brilliant evil smile.
“You know what I've come for,” he said.
“You can't escape me.”