Story about History - never quoted

An intelligent 15-year-old high school student is unexpectedly transferred to a boarding school where he opens a portal of monsters from another dimension.

Six children are found spread through out the world that not only have enormous intelligence, but identical intelligence and have a strange bond to each other.

Jonathan is a young man with a strange condition that only his brother understands. But when he begins to yearn for a different life, their unique bond becomes increasingly tested.

When Hilda wakes up in the body of a troll, she must use her wits and courage to get back home, become human again — and save the city of Trolberg.

Two millennia ago, a Lybian king has a basilisk (snake-shaped dragon), which petrifies people, subjected to the same fate with a golden scepter during a solar eclipse. Both these and several victims are dug up by modern archaeologist Harrison 'Harry' McColl's expedition. Despite a cryptic warning from tribal locals, everything goes to his Colorado university's museum. It's all exhibited during another eclipse, which leads to the monster reviving. Harry and some of his friends must try to petrify the monster again.