Kate never felt more at home than in the company of her grandfather in his New England kitchen. She is the only soul capable of coaxing him away from his mysterious experiments in astrophysics long enough to enjoy picnics in the garden. And only Grandfather’s gentle humor could lift Kate out of her doldrums.

But Kate’s world is about to be turned upside down. Grandfather’s research has attracted some unwarranted attention as an otherworldly visitor nearly destroys his laboratory. And before he can fully reveal why he has been seeking the connection between the nature of light and the nature of the human soul, he disappears—leaving Kate to search for him…and for the secret that can save Earth and the entire solar system from annihilation.

“An ethereal quality pervades the entire Heartlight narrative with a glowing core of hopefulness…it flows like a strong, smooth river in continuous dreamlike motion to a satisfying yet poignant conclusion…an excellent story.”—Brian Jacques

“Heartlight…crosses generational lines and becomes a vehicle for family discussions about love, death, independence, and integrity.”—Rocky Mountain News

“What a joy to read…The author manages to combine sophisticated concepts of physics with high fantasy in a marvelous way.”—Madeleine L’Engle

“A splendid action-adventure science fantasy filled with deep, resonant emotional and spiritual undertones…This book shines as a bold, original effort worthy of repeat readings.”—Publishers Weekly

“Like Madeleine L’Engle, T.A. Barron very persuasively and very plausibly compounds great galactic adventure with questions fundamental to the universe—ours or any other.”—Lloyd Alexander

“This thoughtful adventure combines fantasy, physics, and metaphysics in a manner reminiscent of Madeleine L’Engle.”—Booklist