All You Desire by Kirsten Miller
At the end of the first book, Haven and Iain, having faked his own death, escape to Rome where they spend a blissful year. This is where All You Desire picks up - one year later in Rome. Haven is called back to New York when Beau, her best friend (and brother in their past lives) suddenly goes missing. Haven is forced to enlist the help of an underground group called the Horae to save Beau, and in exchange for their help becomes a pawn in their plot to destroy Adam Rosier and the Ouroboros Society. In the process, Haven finds herself drawn to Adam and questioning and risking everything and everyone important in her life.
All You Desire was a good follow up to The Eternal Ones. I enjoy the series, and am intrigued by the idea of past lives, which is what originally drew me to the series. Many of the characters experience "flashbacks" that appeal to the historian in me - All You Desire has Haven reliving a past life in Florence at the outbreak of the Black Death. It's not the best series I've ever read, and it's not one that I will read over and over again, but Kirsten Miller is a good storyteller and mixes the right amount of suspense in with romance. The twists in the plot are not always predictable, which makes for an interesting read. Like the first book, this is a quick read. I would recommend it if you have a short flight or are just looking to waste away the afternoon.