Clockwork Prince : The Infernal Devices, Book 2 (The Infernal Devices)

Love and lies can corrupt even the purest heart....

In the magical underworld of Victorian London, Tessa Gray finds her heart drawn more and more to Jem, while her longing for Will, despite his dark moods, continues to unsettle her. But something is changing in Will - the wall he has built around himself is crumbling.

As their search for the truth leads the three friends into peril, Tessa's heart is increasingly torn, especially when one of their own betrays them.