The Institute is in full swing as everyone is preparing for the wedding of Alec and Lydia. Lydia is getting final touches made on her wedding dress, and Isabelle is trying to figure out a way to throw a traditional, mundane bachelor party for her brother. Alec is struggling on two sides – his parabatai should be at his side on his wedding day, yet he and Jace are still at odds. Alec also continues to struggle with his feelings for Magnus, especially when Magnus won’t give up on Alec. Meanwhile, Jace, Clary and Magnus go looking for warlock Ragnor Fell to try to find the antidote to awaken Jocelyn.