In the third episode, the discovery of extraterrestrial life might face an impossible challenge: the physics of the universe itself; but using cutting-edge tech, experts might be on the verge of a groundbreaking find -- and the evidence could already be in hand.

Does the universe, have a limit? Does the universe have an edge? Looking out to the edge of the universe is tremendously important to understand our place in the cosmos and to understand the universe itself.
Inflation was a formative moment for our universe. By the time it stopped, the universe's basic characteristics were set. There could be regions of the greater universe where inflation didn't stop then. Occasionally a little region will stop inflating and just expand at the normal rate. We could imagine a super large-scale structure where there's different regions of the universe, domains, and each domain has different local constants and laws of physics.

The center of our galaxy is one of the most nightmarish places in the cosmos. It's the home to some of the most incredible forces the universe has to offer. Gas streaming everywhere, stars are being born and dying and exploding, radiation blasting out. And at the very heart is the super massive black hole, 4 million times the mass of the sun. But also the Milky Way, is our safe harbour, our island in this vast, cosmic ocean. And so to understand the heart of our galaxy, is to understand our home in this cosmic void.

Schwalmstadt Maximum Security Prison in Germany. Locked up behind the walls of this 12th-century castle are 188 of Germany's worst offenders. The prison is a fortress surrounded by a moat, and houses dangerous criminals, many of whom attend intense therapy sessions.

David Attenborough reveals the extraordinary ways that some animals use colour to hide and disappear into the background. New science reveals how the Bengal tiger in central India uses its orange-black stripes to hide from its colour-blind prey. In Kenya’s Masai Mara, the zebra’s black-and-white pattern confuses predators with an extraordinary effect called motion dazzle. And on the island of Cuba, a small snail uses colourful stripes in a surprising way to hide from its enemies.
Other animals use colour to trick and to deceive. On Australia’s Great Barrier Reef, a blue-striped blenny uses colours to mimic other fish and launch a sudden attack. In the grasslands of Zambia, the chick of a pin-tailed whydah mimics the patterns of its nest mates to ensure that it is not detected as an imposter. And specialist cameras reveal how a tiny crab spider uses bright ultraviolet colours to lure in its victims.

This brilliant docuseries is an exploration of the feudal Japan from 1551 to 1616 , during the final phase of the Sengoku period (The Age of Warring States), when several powerful daimyo (warlords) fought to become absolute ruler. It features reenactments of historical events and commentary by voice-over artist Hiro Kanagawa and outstanding historians.
In the first episode, Oda Nobunaga becomes head of the Oda clan upon the death of his father, but this causes problems with family members who compete for control.