A marine biologist’s quest to study and understand the language of light in the breathtaking darkness of the deep ocean, the largest and least understood habitat in the world.

Edie Widder is a scientist, an explorer, an inventor, and a trailblazer. Her career as an ocean-going marine biologist is a highlight reel of adventure and discovery. In hundreds of deep dives her quest to observe, understand, and even interact with bioluminescent animal life has taken her to some of the most remote and inhospitable places on Earth. She’s the first person to film a living giant squid, she’s the recipient of a MacArthur Genius Grant, she has given three TED talks (7 million cumulative views). Edie grew up determined to be a marine biologist but a botched surgery during college caused her to go blind, a temporary condition that left in her a fascination with both light and the power of optimism. Her focus turned to oceanic bioluminescence, a scientific frontier requiring a brave and very literal leap into the darkness. On her first ever visit to the deep ocean, in an experimental diving suit that took her to a depth of 800 feet, she turned off the suit’s lights and immediately witnessed a dazzling display of lights and colors made by creatures invisible with the lights on. Concerns about her career went out the window. "I just wanted to know why. Why was there so much light down there?” BELOW THE EDGE OF DARKNESS takes readers deep into our planet’s oceans as Widder pursues her questions about one of the most important and widely used forms of communication in nature. In the process, she reveals hidden worlds and a dazzling menagerie of behaviors and animals, from leviathans to shrimp, many never-before-seen. We live through life and death equipment malfunctions, witness breakthroughs in technology and understanding, all of it set against a growing awareness of the deteriorating health of this, our largest and least understood habitat.

Dr. Edith (Edie) A. Widder is a former senior scientist at Harbor Branch Oceanographic Institution and co-founder of the Ocean Research and Conservation Association.