My book. The abandoned house.

One day, Amy and her friens decide to explore an abandoned house after school.
Amy must stay in detention, so they arrange to meet later.But amy doesnt arrive!amys friends go to the school to look for her.
they dont find amy, but theydiscover some other strange things.
what happened at the scoolthat day? where is amy?What is the connection between these events and the abandoned house?