Super Short Summary

Dragonflight by Anne McCaffrey is set in the star system of Rukbat on the planet Pern, whose society now mirrors medieval Europe. The planet is threatened intermittently by the deadly Threads that fall from the Red Star. The dragonriders, who are tasked with defending Pern from the Threads, have fallen into disgrace due to the long absence of Thread attacks. F’lar, a dragonrider, finds Lessa at Ruatha Hold and brings her to Benden Weyr, where she becomes bonded with a queen dragon, Ramoth. Together, they restore the Weyrs' readiness, ultimately using time travel to bring reinforcements from the past to combat the looming Thread threat.