Good mix of intense suspense and a long-building romance. K-9 handler Serena Lopez gets a shock when the Tactical Crime Division's latest case hits close to home. They must track down a trio of escaped prisoners, one of whom is her half-brother. Her partner for this op is the frustratingly calm and efficient Axel Morrow.

In the series's earlier books, I felt a certain amount of tension between Serena and Axel. That tension becomes more evident in this book as they work together to track the escapees. Serena is well aware of the effect Axel has on her, but a previous workplace relationship turned out badly, so she is wary of giving in to it. Axel is equally attracted to Serena and has his own doubts and conflicting emotions to deal with, which he does by burying them deep.

I liked watching the development of the relationship between Axel and Serena. They've worked together for four years, and their attraction has simmered for almost as long. The intensity of their situation brings the feelings they've hidden so long to the surface. They are also more in tune with each other than either expected, which creates a few uncomfortable moments. Serena learns of the tragic past that set Axel on his FBI path and drives his compulsions when it comes to murderers. She aches for the guilt he feels and sets out to help him overcome it. At the same time, Serena shares her half-brother's story and its effect on her and her family. Axel helps Serena see that she has her own guilty feelings to deal with. One of the things I liked best was the respect each one had for the other's abilities. Axel had his protective feelings toward Serena, but he didn't let it interfere with her doing her job. That became even more Important as they closed in on the fugitives. When it was all over, Axel and Serena had to decide what to do about their future. I loved Axel's confidence in the face of Serena's worry over what their teammates would say. I loved the scene after Axel got out of the hospital and his friend/teammate Max took him home. The epilogue with the post-case party was terrific.

The suspense of the story was excellent. From the moment they learned of the escape, I could feel the TCD's determination to capture the fugitives before they could cross the border. With Axel, Serena, and her dog Blanca in the lead, it was fascinating to watch their plan unfold. The closer they got, the more questions they had about what the fugitives were doing. The first confrontation raised concerns about what kind of outside help they received, while Axel and Serena overheard something alarming. After a break to treat injuries and rest a little, Axel and Serena intensified their pursuit and came up with a plan to separate the bad guys. An unforeseen twist put Serena at the mercy of a man with nothing to lose. I was on the edge of my seat as the scene played out, wondering what would happen. The turning point came from an unexpected source, but it was still a close call.

Another essential part of the story was the relationship between Serena and her sister, Opaline, another TCD member. In the earlier books, the tension between the two women is obvious. In this book, we finally learn that it is rooted in family issues, mainly dealing with their half-brother. The two women's attitudes are very different, and it isn't surprising that they clash. There is a very rough patch near the end, but Opaline comes through, which goes a long way toward redeeming her. ( )