Clockwork Angel (The Infernal Devices, #1)

When Sixteen-year-old Orphan Tessa Gray's Older Brother Suddenly Vanishes, Her Search For Him Leads Her Into Victorian-era London's Dangerous Supernatural Underworld, And When She Discovers That She Herself Is A Downworlder, She Must Learn To Trust The Demon-killing Shadowhunters If She Ever Wants To Learn To Control Her Powers And Find Her Brother.