I've not read anything by de Vigan before, but she's very popular for her psychological fiction in France! I did like this one and, despite a slightly abrupt ending, will definitely read more by her in the future. Loyalties is about the ties that bind us all in different ways, between friends, parents, teachers and students. It reminded me a little bit of Confessions by Kanae Minato, probably because of the dark themes and the school setting! The short chapters make it super easy to read in one sitting and I enjoyed the glimpse into the inner, secret lives of the characters, disturbing as some of them may be!