A man wants to get back his best friend from a cartel. A woman wants to protect her sister and get out. Can they work together and bring down the cartel and still fall in Love? They're RELENTLESS in their pursuit of each other and the cartel. Elizabeth Dyer continues her Somerton Security series with the story of Ethan Somerton and Natalia Vega, and how their journey through the dangerous world of a drug cartel affects their lives and the people around them. The story picks up a few months after the first book in the series, DEFENSELESS.

Ethan is on the downhill side of his recovery from being shot, but that won't stop him from trying to save one of his top agents and best friend from the dangerous Vega cartel. The Vega cartel has had this agent in captivity for over a year, and Ethan plans on going undercover as an accountant for the cartel. At a party to be introduced to the local cartel leader, he flirts with the two Vega sisters and is drawn to the oldest, Natalia, but knows he has to be careful around her. Natalia doesn't trust Ethan and thinks there is something off about him. She is also caught between keeping the promise to her father and trying to keep from being abused or killed by her uncle who is the head of the Vega cartel in DC.

Even though they both aren't totally sure about the other, Ethan and Natalia can't stop the attraction between them from growing, and they learn to trust each other and begin a physical relationship. Ethan is still trying to find where they are keeping his friend, while Natalia is finding out what the cartel is really up to, and she's not sure she wants to be a part of it in the future. Natalia asks Ethan to promise to protect her sister while she buys time for them both to figure things out. But as things heat up between them, the nefarious cartel leaders are up to no good. Will Ethan and Natalia believe in the trust they have in each other to survive?

RELENTLESS keeps you on the edge of your seat to see what will happen to Ethan and Natalia. Will they be able to take down the cartel and save their loved ones while doing so? Will the information uncovered keep them apart or will they come together and love conquers all? Who is the next to become entangled in a situation and find love from the Somerton Security Agency. I look forward to finding out in the next book in the series and see where Parker and Georgia's lives are, along with Ethan and Natalia, too.