Simon & Schuster has signed books five and six in Cassandra Clare's bestselling YA series, The Mortal Instruments. S&S says there are more than three million copies of the series' three published titles in print. Clare launched The Mortal Instruments in 2007, with City of Bones, about a teenage demon slayer; City of Ashes and City of Glass followed. Book four, City of Fallen Angels, is scheduled for April 2011.

Karen Wojtyla, editorial director of Margaret K. McElderry Books, bought U.S. rights to the two new titles from Barry Goldblatt at Barry Goldblatt Literary. The two new books under contract--City of Lost Souls and City of Heavenly Fire--are scheduled, respectively, for May 2012 and September 2013.

Clare will also be touring, in late August, to promote Clockwork Angel, which is the first title in the prequel series to The Mortal Instruments, The Infernal Devices. Film rights to The Mortal Instruments have been optioned by Unique Features.