Keegan Whitestone doesn't believe in magic. A disillusioned young man drifting through life without purpose, he almost welcomes the unexpected delivery of his father's signet ring and a mysterious note. Estranged from his father before the man's death, Keegan knows nothing of his family heritage, or of the world awaiting him on the other side of the magical barrier known as the Veil. Summoned by the grandfather he never knew existed, Keegan must travel beyond the Veil to become the older man's apprentice. With his grandfather, known as the Guardian, they must safeguard the barrier tethering together the worlds of science and magic. Someone - or something - is at work trying to break that barrier and bring the long separated worlds together, to subjugate the human race on both sides. Before he can become his grandfather's apprentice, Keegan must gain the approval of the High Council, a group of witches and wizards more interested in advancing their own agendas than in protecting their world. If he wins their approval, he must survive training under the tutelage of his grandfather's assistant - a wizard convicted of treason some five-hundred years before and sentenced to spend all but one hour every day as a black cat. Learning to control the power within proves harder than he thought, but when he tries to return home he learns the shocking truth - his grandfather's enemies want Keegan dead whether he's an apprentice or not. If he doesn't find the inner strength to control his power, both worlds could perish as the ancient portal is unsealed and the Shadow is unleashed upon mankind.