Theodosia and the Serpents of Chaos - Robin LaFevers

Theodosia Throckmorton has an extraordinary ability: she can sense ancient magic. This is most useful, as she spends her life fighting curses in the London Museum of Legends and Antiquities, where her father is head curator of a vast collection of Egyptian artefacts and mummies. When Theo's mother returns from an archaeological dig bearing the Heart of Egypt, a legendary amulet from a long-lost tomb, Theo soon realises it holds a powerful curse which could threaten all of Britain with war. Worse, there are sinister forces who wish to capture the amulet's power for themselves. Theo must summon all her courage and cunning to fight the rising chaos and restore the amulet to its rightful place...