Philomena Church has always been good study-buddies with Thomas Lightwood, and nothing more. But when she stumbles upon him collapsed on the ground and in pain one night, everything about their relationship changes. With one touch, she's thrown to the ground and when she wakes up, Tom is nowhere to be found. Lo isn't one to forgive and forget, and when she starts hearing Tom's voice inside her head, she corners him to demand the truth.
Lo is soon dragged into a world she never knew existed, one of superheroes and sidekicks, of good and evil, one where Tom is supposed to fall in love with her, but swears he can't. She's supposed to have Tom's back regardless, have unwavering loyalty to him, but when his twin brother, Jonathan, shows up, Lo suddenly finds herself torn. Jonathan is the one she's pulled to, the one who makes her heart race, but he's already chosen his pathdarkness, the opposite side of Tom.
Lo finds herself facing an impossible choice: side with the evil twin who she loves, or the good twin she's obligated to help but claims can never fall in love with her. Can she save Jonathan without condemning Tom at the same time?