Scattered across the night sky in immense numbers are the alchemists of our cosmos - the stars. They forge new elements inside their raging nuclear core and cast them out in cataclysmic supernova explosions. Many of these extreme monsters grow hundreds of times larger than our Sun and burn over million times brighter. But could the life and death of the most extreme stars in the cosmos be key to understanding our very existence? This episode follows scientists investigating some of the earliest stars in the universe, over 13 billion years back in time. Astronomers at Jodrell Bank in the UK reveal how even inside the aftermath of a massive stellar explosion, a freakish zombie star that cannibalises others can rise from the dead. We join astrophysicists working in laboratories hidden under the Gran Sasso mountains in Italy who are hoping to foresee a supernova explosion. CGI animation will tie together clues from ongoing scientific missions around the world and reveal how integral stars...