With the killer's identity - and twisted motives - revealed, the group finds more key clues as the global police manhunt reaches a fever pitch. A question arises: Were we complicit in his crimes? Did we feed the narcissism of the monster to the point where he had to go forward?

We routinely talk about healthy food and clean water, but how often do we spare a thought for what enters our lungs? The World Health Organization calls air pollution the silent killer. Air pollution is proven to shorten our lifetimes and it hits the vulnerable - children, the sick and the elderly - hardest of all.
Prince William, Sir David Attenborough and astronaut Naoko Yamazaki hear the personal stories of people who are directly affected by air pollution and show us incredible solutions.

Seafood is a substantial part of the daily diet of over three billion people and oceans absorbs almost a third of all the greenhouse gases we emits. Buy the ocean it is not what it once was. Scenes of extraordinary ocean abundance now only exist in far-off places or in tales from the past. We urgently need to mend our relationship with our oceans and allow them to thrive once again.
Prince William, David Attenborough and Shakira find out about inspiring people and projects across the world that can help us stop damaging the oceans and enable their revival.

The plains of Africa, home to a powerful predator where females rule: spotted hyena. They have a reputation as dim-witted scavengers. But these fierce queens are the opposite; strong, fearless and highly intelligent. Hyenas are the girl gang of the Savannah. They hunt in packs, get first bite of their prey, and outrank every male in their group, making them some of Africa's most fierce queens.

In America the summer twilight brings out a magical display of glittering lights. Millions and millions of fireflies, an ethereal sight. But behind this twinkling facade is a fierce female setting a deadly trap. The femme-fatale of fireflies is part seductress, part vampire, as Reese shows us the fireflies' deadly trickery to provide nourishment to their young.

Professor Brian Cox continues his epic exploration of the cosmos by looking at the faint band of light that sweeps across the night sky - our own galaxy, the Milky Way. The Sun is just one of almost 400 billion stars that form this vast, majestic disk of light, our own home in the universe. Thanks to a cutting-edge space we’re finally able to reveal the Milky Way’s dramatic history and predict its cataclysmic future.
Our galaxy started out a fraction of the size it is today, and Gaia telescope has revealed how it grew over the eons. Beautifully rendered VFX based on the very latest Gaia data has uncovered the remarkable story of our galaxy’s evolution. As our young galaxy encountered rival galaxies, it experienced a series of violent growth spurts and intense periods of cataclysmic change while battling to survive. Each time our galaxy feeds, a new era of star formation begins, fuelled by incoming torrents of fresh gas and energy. And there is another collision to come. Another, larger galaxy is coming our way. Andromeda is heading straight for us at a quarter of a million miles per hour. The Milky Way’s long-term fate is in the balance.