Jeffery Deaver’s XO is the latest installment in the increasingly popular Kathryn Dance series. His protagonist, an agent of the California Bureau of Investigation and a body language analysis expert, uses her talents and skills to great effect in a tale that’s a bit of a departure from Deaver’s previous books.

"Edwin Sharp is one of Deaver’s best antagonists yet, because he is so real.... As far as the narrative is concerned, Deaver is at the top of his game... Set aside several hours for XO; once you start it, you will want to read it in one sitting."

How so, you ask? Deaver has come to be known for writing plot-driven works that take the reader’s assumptions, twist and turn them, and rock them upside down and back again --- sometimes with sleight of hand, other times with some gentle misdirection. XO does not do that, or at least not quite as much as, say, Deaver’s Lincoln Rhyme novels. This is a straightforward thriller, creepy as all get-out, with a very smart and dangerous antagonist and a clock that starts ticking the second the reader opens the book.

XO kicks off with a set of email exchanges that set the mood for the entire novel. The correspondence is between Kayleigh Towne and Edwin Sharp. Kayleigh is a country music superstar from Fresno, California, and Edwin is a huge fan of hers --- too big a fan, actually. He believes that the affectionate tone of the letters that Kayleigh’s office sends to all of her fans contains words of love meant just for him. In fact, he believes that Kayleigh’s hit single “Your Shadow” is directly about him. In these few opening pages, Deaver demonstrates yet again the true depth of his talent: read a few sentences in Edwin’s emails, and you can feel your scalp creep and your skin crawl. By the time Edwin is introduced, you want to jump into a hot shower.

Kathryn, who is a friend of Kayleigh’s, has taken a few vacation days to attend her homecoming concert in Fresno and walks right into the middle of a dangerous situation. Just hours before she arrives in Fresno, an accident during Kayleigh’s rehearsal almost seriously injures the singer. Hours later, a member of her stage crew is killed in a similar incident, which is quickly determined to have been staged.

Meanwhile, Edwin has become Kayleigh’s shadow, literally; he has come to Fresno to attend the concert, rented a house for an entire month, and is showing up in all of her familiar haunts. Worse, he seems to know where she will be, what her new phone number is, and all sorts of things about people connected to her, including her assistants and local law enforcement. He is the number one suspect in the death of her stage manager, but there is no proof that he committed any crime. And it looks like he’s just getting warmed up. Kathryn’s presence draws Edwin’s attention toward her, and to make matters worse, she also finds that the local deputy regards her assistance in the murder investigation as unwelcome. It quickly becomes all too clear, however, that the killer, whether it be Edwin or someone else, isn’t about to stop with just a single murder. As the days countdown to Kayleigh’s long-anticipated homecoming concert, Kathryn and Kayleigh find that they may well have much more to worry about than Edwin.

Edwin Sharp is one of Deaver’s best antagonists yet, because he is so real. Persistent, always wrong but never in doubt, he is single-minded in his pursuit of Kayleigh and will certainly remind each and every reader of at least one person who they have encountered in their past. As far as the narrative is concerned, Deaver is at the top of his game, stretching his story over a relatively short period --- six days --- and confining the action almost exclusively to a few blocks of Fresno, yet wringing the maximum drama and suspense out of each and every page. Set aside several hours for XO; once you start it, you will want to read it in one sitting.