In the second episode, Dreadnoughtus males compete for the right to mate. Lizards are hunted by Velociraptor among a group of sleeping Tarbosaurus. A Mononykus forages for termites and investigates new food options after a brief rainstorm. Several types of dinosaurs congregate around a watering hole in Mongolia. Above the deserts of North Africa, aerial combat ensues as male Barbaridactylus pterosaurs fight for the attention of females below. A herd of Secernosaurus brave the harsh gypsum dunes in search of nourishment.
In the third episode, a Velociraptor hunts pterosaurs on a cliffside by a waterfall. A battle-scarred Tyrannosaurus nurses his wounds and encounters a newcomer. With its feathered body and duck bill, the eight-ton Deinocheirus wades through an Asian wetland in search of relief from pesky biting flies. A female Quetzalcoatlus builds and guards her nest. A mother Masiakasaurus and her family hunt crabs. Elasmosaurs enter an estuary in search of fish.
In the last episode, Austroposeidon level trees in search of fresh foliage. A herd of Triceratops journey through a cave to find an underground clay lick. A male Carnotaurus sets the stage for an extravagant display. A female Qianzhousaurus uses an autumn storm to her advantage while hunting Corythoraptor. A family of Edmontosaurus evade a forest fire, while an Atrociraptor and Ankylosaur reap its rewards. Juvenile Therizinosaurus attempt to climb up to a bee nest. Hatzegopteryx hunts Zalmoxes, and patrols the dense undergrowth and seaspray-battered coastline.
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.
A female Phosphorosaurus hunts lanternfish under the ocean's moonlit surface. Hesperornis hunt for fish until they themselves are hunted by Xiphactinus. A Mosasaurus hunts a group of Tuarangisaurus. Nostoceras hatchlings are at the mercy of the tides and juvenile Pyroraptor. The young Nostoceras that survived find themselves among Baculites and Diplomoceras in their new seagrass meadow home. A pod of Morturneria sift the muddy seabed in search of food.
As summer spreads across our planet, honey bees toil, snow geese breed, tadpoles awaken and lions stalk wildebeest in search of lush grass. Our planet is solar-powered. But due to the Earth's tilt, it doesn't strike its surface evenly. This solar energy arrives in varying amounts at different times of the year. The huge increase that comes with summer also triggers countless migrations.
Above the deserts of North Africa, aerial combat ensues as male Barbaridactylus pterosaurs fight for the attention of females below. A herd of Secernosaurus brave the harsh gypsum dunes in search of nourishment.