Neil deGrasse Tyson sets off on the Ship of the Imagination to chase a single comet through its million-year plunge toward Sol. Later, Tyson visits the birth-place of Sir Isaac Newton and retraces the unlikely friendship between Newton and brilliant polymath Edmond Halley. It was Halley's patience and generosity which allowed Newton to conquer his fear of isolation and find the courage to publish his masterwork, "Principia Mathematica" which launched a scientific revolution.