In the Days of the Comet - H.G. Wells

A comet rushes toward Earth, a glowing orb filling the sky, promising doom. Humanity is too busy hating, stealing, scheming & killing to care. As luminous green trails of cosmic dust & vapor stream across the heavens, blood flows beneath: nations wage wars, bitter strikes erupt, jealous lovers plot revenge & murder. Earth slips past the comet by a narrow margins, but all succumb to the gases in its tail. When everyone wakes up, they are completely & profoundly different.
In the Days of the Comet is Wells's tale of the last days of old Earth & the extraterrestrial change that is the salvation of the species. An ill-fated romance between Willie Leadford & Nettie Stuart unfolds in a world buried in misery & bent on destruction. After Earth passes thru the comet's tail, suffering, pettiness & injustice melt away. Willie, Nettie & all around them are reborn. They now see themselves & their world in a dramatically new way.