"Radiant Sin" by Katee Robert The fourth book in Katee Robert's "Dark Olympus" series, "Radiant Sin" follows retells the Greek myth of Apollo and Cassandra with a modern twist. It follows Cassandra Gataki, who is asked by the god Apollo to go undercover and attend a party with him as his plus-one. Their fake relationship escalates — and so does the heat. Release date: Feb. 7 Image Source: amazon.com