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.

In this mind-bending series, Professor Jim Al-Khalili explores the vast range of size in the universe, from tiny atoms to gigantic, interconnected galaxies.
In the first episode, Jim will enter the world of objects that are too tiny to glimpse with the naked eye. Starting with the smallest insects, he moves on to encounter living cells with amazing superpowers and confronts some of humanity's deadliest enemies in the form of viruses. Going smaller still, he encounters wondrous new nanomaterials such as graphene, discovered by physicist Andre Geim. These are revolutionising engineering, medicine, computing, electronics and environmental science. Finally, Jim comes face to face with the fundamental building blocks of the world around us – atoms – and reveals why understanding the science of the 'small' is crucial to the future of humanity.

Female Isisaurus traverse the Deccan Traps to reach their nesting site. A mixed herd of sauropods and Prenocephale navigate a maze of canyons, but are ambushed by a pack of Velociraptor and a trio of Tarbosaurus. A colony of male Corythoraptor protect their eggs from the scorching sun by day, and a female Kuru kulla at night, who has offpsring of her own.
Trudging through a scorching desert, two young Tarchia find relief at an oasis and encounter an adult twice their size, ready to lay claim. Several Isisaurus hatchlings fall prey to Rajasaurus in an attempt to reach their ancestral home.

Pterosaur hatchlings take flight to leave their island sanctuary, but are targeted by several Shamosuchus. Several Austroraptor hunt garfish and contend for the best fishing spots. A male Beelzebufo attempts to attract a mate, but his endeavor is interrupted by a herd of Rapetosaurus. A male Pachycephalosaurus must put an upstart youngster in his place. Two Tyrannosaurus brothers hunt Edmontosaurus under the cover of darkness.

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.

A Tyrannosaurus and two Quetzalcoatlus fight over an Alamosaurus carcass. A shoal of Sphenodiscus are ambushed by a Globidens, intent on surplus killing them. At an evaporating lake, juvenile Pectinodon hunt flies while their father hunts Styginetta. Male Triceratops fight and display for the right to mate. A female Nanuqsaurus hunts Ornithomimus to feed herself and her offpsring.