Finale (#4) by Becca Fritzpatrick

Fates unfurl in the gripping conclusion to the "New York Times"-bestselling Hush, Hush saga. Nora is more certain than ever that she is in love with Patch. Fallen angel or no, he is the one for her. Her heritage and destiny may mean they are fated to be enemies, but there is no turning her back on him. Now Nora and Patch must gather their strength to face one last, perilous trial.