The Keepers' Tattoo — Gill Arbuthnott

Ten years ago, Alaric, leader of the Shadowmen, killed most of the Keepers--teachers of ancient knowledge that threatened his barbaric rule. Young Kit was captured, but his twin sister, Nyssa, escaped. Only later will she learn that both she and her lost brother bear the secret words of their people: three lines each of strange, unintelligible writing tattooed on their scalps. Now the Shadowmen are on the attack again, determined to quell a growing rebellion. Nyssa must find her brother, and together they must unlock the meaning--the power--behind the mysterious words.