The images of brothers Tamerlan and Dzhokhar Tsarnaev are released to the public setting off a violent chain of events. Meanwhile, clues from their past tell a complicated story - how was the radicalization of the ethnically Chechen brothers and the existence of potential collaborators. The post-9/11 biases played a role in the investigation.

Following their identification, the Tsarnaev brothers killed an MIT policeman, then kidnapped a man in his car. They had a shootout with the police in nearby Watertown, during which two officers were severely injured (one of whom, Dennis Simmonds, died a year later). Tamerlan was shot several times, and his brother Dzhokhar ran him over while escaping in the stolen car. Tamerlan died soon after.
An unprecedented manhunt for Dzhokhar ensued, with thousands of law enforcement officers searching a 20-block area of Watertown. Residents of Watertown and surrounding communities were asked to stay indoors, and the transportation system and most businesses and public places closed. After a Watertown resident discovered him hiding in a boat in his backyard, Dzhokhar Tsarnaev is cornered into an intense standoff. As officials navigate remaining questions and suspicions, the city emerges Boston Strong.

Continuing your bloodline is life's ultimate mission. In this unpredictable world, animals will do whatever it takes to keep their families safe. When family sticks together, communicating, collaborating and combining as one, everyone has the very best chance of survival. It takes every superpower possible to protect and provide for the family and secure the future for a new generation of amazing animals.

Predators and prey are in an arms race for survival. Hunters and hunted deploy hidden super- skills in the battle to eat or be eaten. Masterclasses in predatory perfection are vital to passing on skills. So when they're ready to hunt for real, the next generation is fully prepared for the battle between predator and prey.
Life is a mission, survival. Animals have evolved secret weapons and hidden skills to outsmart their enemies. So in those life or death moments, it takes the most extraordinary super powers to prevail.

We may be smart, but we're still discovering animals have countless skills, every bit as impressive. In a world full of unexpected foes, competition is evolution's ultimate driving force. Is the secret behind the incredible diversity of life on earth, and the most extraordinary animal powers.

In the quest to pass on their genes, animals use incredible skills to win a mate. And spectacular displays to beat their competition. When the fight for mates gets fierce, it could take super strength and secret powers just to keep rivals at bay. After all, when it comes to sharing your future, only the most super-powered partner will do.