The Baltimore Rock Opera Society was formed by a small group of friends in 2007. Today the BROS boasts over 300 members. For their recent large-scale production, Murdercastle, the BROS had 99 days to build the original rock opera from scratch. Murdercastle: How to Make a Rock Opera takes a tender look at the life of serial killer H. H. Holmes’ infamous “Murder Castle,” a hotel he built with hidden passages and secret rooms to murder 27 guests in 1893 Chicago.