Why are there strange occult books in its library, living gargoyles on its cornices, and cannons in its belfrey?

Edward is barely introduced to the house's many secrets and his new teachers, Dr. Basileus and the partly robotic Zarcon of the planet Zarconax when the place comes under attack by Ghastly Horrors.

Then sister Margaret, seeking a better internet connection, opens a window and accidentally lets them in.

After that things start happening really fast, with the adults out of commission and the children in the clutches of the sadistic Mrs. Morgentod, and the fate of the entire universe in the balance.

In his review of The Dragon House, Stanford University's Brian Kunde praised the novel, noting in particular its fast pace, interesting characters, unique setting and bright tone.