Arguably the most famous story arc in comic book history. 1st appearance of the Silver Surfer and Galactus - and Wyatt Wingfoot for that matter. The Surfer blows into town and tags earth as the next food feast for Galactus, which would essentially be the end life as we know it - on this planet anyway. The Fantastic Four step up to save the day, of course. It is what they do. Lee and Kirby at their best.
Eventually, I will have all FF V1 comics scanned front and back on my website. What I have so far can be found here: https://dekventures.com/FantasticFour/fantastic-four-v-1-regular-issues