Tessa Gray was once an average teenage girl and when her aunt dies she goes to England to meet her brother. But there to pick her up is two women that call themselves the dark sisters. They knew that tessa has powers so they would get tessa to work on her powers for hours and hours. Then one day a boy named will herondale came and saved Tessa and brought her to the institute. The magister doesnt like how Tessa escaped the dark sisters so comes after her but she has to figure out who the magister is. Tessa finds herself falling for two shadowhunter boys, Will and Jem/James. Tessa doesnt know who to choose because Will is charming, witty, dangerous and daring. But Jem is sweet, sensitive and would help her before himself. At the end someone unexpected is working for the magister and turns out her aunt was killed by someone trusted.