In “The Underworld,” journalist Susan Casey takes readers into the deep ocean to explore volcanoes, trenches, and a booming ecosystem that’s vital to our survival.

Corinne Bailey Rae talks about “Black Rainbows,” which took seven years to make and was inspired by Chicago artist Theaster Gates. 

In “Egg,” author Lizzie Stark explores the history of the egg, from Gold Rush-era gang wars in San Francisco to vaccine development and chickens in space.