RYAN BOOTH is an ex-Marine and he's not just at Quantico to train. His relationship with Alex is complicated, sexy, dangerous and frustrating. His relationship with the Bureau at Quantico and after the Grand Central bombing is just as complicated. Between his first day at Quantico and the day of the bombing, Ryan goes from a man who follows orders to a man who follows his instincts (and sometimes his heart.) From the second he met Alex, he was embroiled in her life even when he knows it might ruin his career. Though he may appear polite and respectful, Ryan is a soldier who has seen battle, and has watched his fellow soldiers be blown to bits, and that memory haunts him. He has scars that remain unseen by his friends, co-workers and the women in his life. A strong presence at Quantico, Ryan's calm demeanor is at odds with the power he has within him. He can kill, he has killed and he will very likely have to kill again to help exonerate Alex Parrish.
(Source: ABC)