Through the Past Deadly - S1.E13

A bomb is planted in Ryan's car and he is injured. Mac tries to find the one who planted the bomb and starts by looking for the one who sold the explosive used. He finds the seller dead and all signs lead him to think it has something to do with a man named Speer who's the man who brought Ryan and Mac together. While waiting for the police to find the one who planted the bomb Mac recalls how they got together. It was two years ago and Mac was trying to get Speer for killing his partner and sought Ryan's help because Speer killed someone close to Ryan.