This post contains lots of spoilers!!
I also read Destroy Me, which is a novella that takes place in between Shatter Me and Unravel Me. This book gives you more of an insight into Warner. Lots of reviewers said that they fell in love with Warner in Destroy Me. Not me. He was a little more likable, but still a jerk.
Wow, this is the rare sequel that is just as amazing (if not more so) than the first! Juliette has teamed up with the rebels and is living with them in their underground outpost. Almost all the rebels have some kind of "gift." Castle, the leader, has telekinesis. Kenjii (who is totally awesome and lovable in this book) can make himself invisible. Juliette's roommates Sara and Sonya have healing abilities. We discover towards the end that James, Adam's little brother, also has healing abilities. Juliette has a cool new suit designed just for her that helps to keep her from accidentally touching and hurting everyone. But everyone is still afraid of her and she's lonely.
Her and Adam are still crazy in love. But he seems distant... Which makes her worry and get a little upset. And that's how we accidentally discover that not only does she have magically dangerous skin, but she also has super strength and can cause mini-earthquakes just by punching the ground.
This is when we find out what Adam's "gift" is - he nullifies other's abilities. So the reason he can touch Juliette is because he nullifies her ability. This happens automatically as a defense mechanism, but it requires energy and so it drains him to touch her. And as he gets more comfortable with her, it's hard for him to feel defensive. Adam is convinced that their relationship can still work. Juliette is willing to give it a try, until she accidentally puts him in the infirmary after a make-out session.
She breaks up with him. They're both sad, but Kenjii forces her to snap out of it. This is when we start to see fantastic changes in Juliette. She becomes stronger and less selfish. Kenjii has her go on a mission with him to resupply the base. She begins to feel like she's part of the community. While on the mission, she sees Warner and sees him playing with a stray dog.
Some members of the resistance are captured by Warner's men. Juliette is part of the team that goes to rescue them. She meets Anderson, Warner's father, and finds out that Warner's first name is Aaron. Anderson tries to get Warner to kill Juliette. Juliette is able to get control of the gun and shoots Anderson in both legs. She's about to kill him when Kenjii bursts in a stops her. Adam also comes in and sees Anderson and recognizes him as his father, who was always abusive and who he thought was dead. They rescue two of their men and take Warner as a hostage.
Castle puts Juliette in charge of interrogating Warner, since he can't touch her. Except...Warner can touch Juliette and she doesn't want anyone (mostly Adam) to know. Juliette's interrogations of Warner turn out to be more like lovely conversations about books and life. She realizes she doesn't hate him, even though she knows she should. And she's eventually able to admit that she's attracted to him. I was afraid this was the direction the book was going in and I didn't want it to, but when it happened, I was totally on board! There is sizzling chemistry between the two. It turns out Warner has an ability as well - he's able to read others' emotions and he can take someone else's ability (they still retain their ability, he just also has it temporarily). Juliette is amazed that he can he touch her, and that it doesn't harm him in any way.
Castle asks Warner to become part of the resistance. Warner accepts, but his ultimate plan is to leave. The residents of the base are very unhappy that he's been let out of his cell. A scuffle ensues, during which Kenjii is injured. After ensuring that Kenjii is going to be okay, Juliette goes back to her room and Warner quickly appears. He wants her to come with him when he leaves. A very steamy make-out session ensues.
But of course, at some point she stops it, because she doesn't want to hurt Adam. Warner is angry that she's denying her feelings for him and that she's choosing Adam over him. She maintains that she's not choosing either one. As much as I wanted Juliette and Warner to happen at this moment, I knew she wasn't going to abandon the resistance and leave with him. She felt a sense of duty to them and she wasn't going to leave.
The next morning is battle. They're going to get back the remaining two hostages. Warner escapes and everyone can't wait to murder him. At some point in the battle, Juliette is knocked unconscious. She wakes up in a house in an abandoned neighborhood. Anderson is there and he wants revenge. Warner shows up and Anderson shoots Juliette.
In the ending chapters, we see through Juliette's haze that Warner is helping to save her with the help of Sara and Sonya.