Water plants create some of the most beautiful, bizarre and important habitats on earth. To hold on in torrents, plants use a kind of superglue. Some are armed with vicious weapons to fight titanic battles for space. Others form perfect spheres and escape from animal enemies by rolling. Where nutrients are washed away, plants turn into hunters of animals, laying traps and even counting to ensure their success.
In this episode we explore those watery worlds with David Attenborough, from Croatia to Brazil, from Colombia to Thailand, the brilliantly coloured flowers smother lakes, and in one magical river in Brazil, the water bubbles like champagne as plants create the atmosphere itself.

Plants that have developed to thrive in the desert, including cacti that grow in the shade of other trees and collect water in pleated trunks that expand and contract - but can also find themselves a host to other plants, like desert mistletoe. This programme also reveals how tobacco plants being eaten by caterpillars are able to summon the creatures' natural predators, and how tumbleweeds roll across the landscape, only unfurling and growing when they encounter rain.

The meteoric rise of renewable energy has consequences for our electricity supply. While coal and gas fired power stations can generate electricity whenever you need it, renewables are intermittent by nature. So we need a backup plan for when the wind stops or the sun goes down.
All over the world, engineers and scientists are racing to solve one key problem; how to safely and efficiently store electricity at a huge scale but at a low cost. The quest is producing some truly remarkable ideas and this episode details three of them.

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 fourth episode, Dromaeosaurs stalk a hadrosaur herd as they cross a freezing river. Male Ornithomimus raid rival nests to bolster their own. Olorotitan raise their offspring on fertile volcanic fields but contend with biting mosquitoes.
Troodontids hunt mammals flushed out by a forest fire. A juvenile Antarctopelta scours the forest for a new winter den. Within the snow-covered forest, a tense standoff develops between ancient rivals, Pachyrhinosaurus and Nanuqsaurus.

In 2011, a Social Security lawyer named Eric C. Conn and a judge named David Daugherty were investigated for committing massive fraud over many years. Conn figured out that he would get paid a hefty retainer for every Social Security disability payment he managed to get approved, so he and Daugherty (who need quick cash to pay for his daughter’s upcoming narcotics trial – which presumably meant bribing an awful lot of people) came to an arrangement.
In the second episode, Investigators starts to collect evidence against Eric and Judge Daugherty. The whistle-blowers are pressured.