The awareness of being mortal distinguishes us from all other living beings on our planet. Without this knowledge, we would probably never have imagined the afterlife and developed the idea of an immortal soul. What happens in our brain at the threshold of death? Do we fly through a tunnel towards the light? Does the chemistry of death ensure that the farewell is accompanied by a great feeling of happiness? Twice in our lives we pass through a portal into a new, unknown reality: when we enter the afterlife and when we see the light of day.

Who realises that we all once lived in a mysterious underwater world? And that with our first breath we took a step that took evolution millions of years? Incredible things happen in the nine months leading up to birth. How does our experience in this strange universe shape us?

For Terra X, Mai Thi Nguyen-Kim embarks on a fascinating, entertaining and sometimes spiritual journey of discovery to find out what we know about the beginning and end of life and what will perhaps remain a mystery forever.