Jace first begins to fall in love with Clary in City of Bones, growing close to her. Isabelle and Alec even later say that they noticed a change in Jace's behavior after he started getting close to Clary. In City of Glass, Isabelle tells Clary that before Jace met her, he was apathetic and only half-alive as if in a long time sleep, but that after their first encounter with her, Jace "woke up" and "started living". She further claims that she has never seen him act the way he does with Clary and firmly states that Jace will never get over her. Throughout the series, Jace continuously loves Clary even when he believes them to be siblings, even to the extent of being willing to commit incest with her and start a secret relationship with her when he believed her to be his sister. He has gotten with many girls before (though it being stated as more as just hooking up) and even tries to start something with Aline Penhollow in a failed attempt to get over Clary. Clary and Jace finally get together at the end of the third book after discovering they are not siblings.