Even perfect families have secrets... Niamh and Conor Ryan are the perfect power couple: smart, successful and beautiful, they have an enviable relationship and an the idyllic family life. But then the unthinkable happens. Their oldest son, Tom, is the victim of a hit-and-run. What was Tom doing out walking so late at night? Did he really have problems sleeping, or was he secretly meeting someone? Is it a coincidence that his friend, Lauren, committed suicide nearby - or is there something more sinister going on? Detective Garda Cathy Connolly is part of the team investigating both incidents. As she delves deeper, she realises that all is not what it seems in the Ryan household and that everyone connected to both cases have their own reasons for hiding things from the police. With her boss and mentor, Dawson O'Rourke, in line for a promotion on the other side of the country, it's time for Cat to consider not only what she wants from her career, but also where their relationship is going. However, when a terrorist threat is unveiled close to home, will Cat be able to put the pieces together in time to save the day? Whatever happens though, there is no turning back...