Guardian is the second book in this series by Claire Delacroix and an improvement on the first instalment, Fallen. That book took a long time to get going, but Guardian starts well with our heroine, Twenty-Three, being kidnapped by a mysterious man. The man calls Twenty-Three 'Delilah' and seems to know things about her. His name is Rafe, and he's mysterious for various reasons - one of which is that he has no memory of his life any earlier than a year previously. Someone is instructing Rafe what to do, but he neither knows who that someone is nor what their motives are.

Delilah knows that she is the Oracle, a woman meant to help guide the President of the Republic and who can speak the words of God through the help of angels. Her situation, however, is fairly dire: there is a false Oracle and, consequently, a price on Delilah's head. Can she trust Rafe? Will Rafe find out who he is? Can Delilah be installed as the Oracle?

Guardian is an enjoyable read with fast pacing and the interesting background setting of the former novel. Rafe and Delilah's relationship is well-written, and despite a few plot holes it's overall an exciting and imaginative book.