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.

We're unlocking the secrets of our planet's voyage and discovering that earth's journey affects us all. The Earth is extremely dynamic. It is spinning on its axis, it's whirling about the sun and it's corkscrewing throughout the this galaxy. And there is the fact than Andromeda and the Milky Way are currently 2.5 million light-years apart, but they're hurtling towards each other at over 250,000 miles an hour. A collision is inevitable. As stars, dust, and gas swirl around each other, gravitational interactions could slingshot our solar system out into intergalactic space.

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.

The tropical island of Mauritius is home to Melrose maximum security prison, where 800 of the country's worst drug smugglers, sex offenders and murderers are locked up. Every convict is watched day and night and even the smallest infraction is met with extreme punishment.

Lesotho's Maseru Central Correctional Institute in Southern Africa holds the country's most dangerous and disturbed criminals. Shockingly almost half the inmates are doing time for rape. The culture of sexual violence in Lesotho has deep roots in society. Women are taken as secondary citizens in their culture. And sexual aggression continues inside the prison.
In this episode, Raphael Rowe will spend a week locked up in this African prison surrounded by sex offenders.