The Sky at Night in the Multiverse of Mystery is a magical journey into the far-flung ideas at the very edge of scientific knowledge, exploring the concepts that today seem like science fiction but may one day become science fact. Delving into the archive at the Royal Society, we look at the dreamers who first considered the possibility of travelling to the moon and black holes long before they could be proven to exist. From there, the team explore some ideas and theories that today could be dismissed as fanciful thinking.