Live Wire by Harlan Coben
Latest in the Myron Bolitar series, an injured basketball player turned sports agent in New York City
Suzze Tervantino, a former tennis prodigy and one of Bolitar's first clients, visits his New York office and shows him a Facebook posting that suggests that her husband, rock star Lex Ryder, isn't the father of the child she's carrying. When Ryder, also a client of MB Reps, disappears, Suzze begs Bolitar to find him. In the process, Bolitar catches a glimpse of his sister-in-law, Kitty, at a crowded nightclub, and begins a search for her and his estranged younger brother, Brad, whom he hasn't seen for 16 years.
With his sidekick, Win, Myron has unexpected encounters with his estranged sister-in-law, who's entangled with rock stars, scandals, and drugs. Adding momentum to Myron's search, his dad suffers a life-threatening heart attack and asks to speak with Brad, his long-lost son. Along the way, Myron confronts his own buried secrets and recognizes that his abandoned sister-in-law and nephew interpret his big-heartedness as unwanted interference.
I'm not sure how I read this book as it isn't the first in the series like I normally do. The book is a kind of roller coaster read as the story was tight and engaging. But I enjoyed the ride. I listened to it on CD so would go back and try one of the earlier book to get a better feel for the series.