Sacrifices
The third book in the Shadow Grail series by the New York Times and USA Today bestselling authors Mercedes Lackey and Rosemary Edghill
The students of Oakhurst Academy believe they have triumphed over the Shadow Knights. But Spirit, Burke, Muirin, Loch, and Addie know better. Under the guise of a company called Breakthrough Adventure Systems, the Shadow Knights have actually taken over the campus. The new regime is brutal, designed to turn the students into soldiers wielding both weapons and magic. Anyone who protests disappears.
Desperate, the group decides that Muirin should go undercover to spy on Breakthrough. But Muirin’s act is a little too good, and Spirit begins to fear that her friend’s loyalties might have truly changed. Surrounded by enemies and friends who suddenly seem like strangers, Spirit has decide who can — and cannot — be trusted.
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Mercedes Lackey
Mercedes Ritchie Lackey (born 1950) is an American writer of fantasy novels. Many of her novels and trilogies are interlinked and set in the world of Velgarth, mostly in and around the country of Valdemar. Her Valdemar novels form a complex tapestry of interaction between human and non-human protagonists with many different cultures and social mores.
Her other main world is one much like our own, but it includes clandestine populations of elves, mages, vampires, and other mythical beings. The Bedlam's Bard books describe a young man with the power to work magic through music; the SERRAted Edge books are about racecar driving elves; and the Diana Tregarde thrillers center on a Wiccan who combats evil.
Shadow Grail
Shadow Grail consists of four books. The current recommended reading order for the series is provided below.

