Andy and Mary are twins. They are thirteen. Still they are not like all other twins. Andy is taller than his sister. He has got red hair and bright blue eyes. Mary is short with long dark hair and big brown eyes. They are not similar in appearance. Moreover, they think differently. The brother and the sister come to Trinity College in Dublin. It is the most famous and ancient university in Ireland. Now they are looking at the book of Kells — a huge volume that is more than a thousand years old. Andy is watching with admiration. Mary is not so interested. She goes to the gift shop. There are lots of T-shirts, mugs and other souvenirs. The girl likes these T-shirts. Except her, there is only one more customer in the store — an unusual man. Later something unexpected happens. Mary is sure it has to do with this man.