Collects Fantastic Four (1961) #575-578.
*Jonathan Hickman and Dale Eaglesham’s critically acclaimed run continues in the Prime Elements, a story that kicks off the new world-spanning adventures of the Fantastic Four. Featuring the return of the Mole Man, the architecture of the underworld, and the smartest Moloid you'll ever meet. Watch as the First Family journeys to the moon where they learn that the history of the Inhumans runs much deeper, and richer, than previously believed. *Source: marvel.com