Welcome to the first day of the City of Lost Souls Rereading, a kind of revising for the release of City of Heavenly Fire that I host, and I'm happy you've come. As you are here I suppose, you know what City of Lost Souls (CoLS) and City of Heavenly Fire (CoHF) are, but if you happen to not, I'll tell you. Both are parts of The Mortal Instrument series by Cassandra Clare. This is one of the several series by her featuring Shadowhunters, whose job is to maintain the piece among the supernatural species and even humans, who by the way know nothing about none of the above mentioned, and kill demons.
