"The Underground ___," Colson Whitehead novel that won the 2017 Pulitzer Prize for Fiction

Lose firmness, as a sofa3 Design detail, for short (anagram of "pecs")4 "Fabled" author of "The Tortoise and the Hare"5 Fruit growing on a vine5 "All good things must come to an ___"3 "Never Have I ___" (Netflix drama)4 Biblical boat builder4 Rounded planetarium roof, say4