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.
Could finding the Magister free Will from his secrets and give Tessa the answers to who she is and what she was born to do?
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.