The Seventh Sacrament is the fifth in the Nic Costa series, David Hewson's detective novels of love and death in Italy. There’s an entire underground city down there . . . houses and temples, entire streets. I talked to a couple of the cavers Leo called in. They hero-worshipped Giorgio. The man had been to places the rest of them could only dream about. Giorgio Bramante, a Roman archaeology professor, was master of the hidden world beneath the earth – until the day he lost his young son, Alessio, to a group of students intent on re-creating a centuries-old ritual to a long-banished god. His rage knew no bounds and, in a frenzy, he beat one of the students to death.