Scientists are learning how we can edit memories—and delete our worst fears. Catch "Memory Hackers," airing February 10 at 9/8c on PBS: http://to.pbs.org/1TGyRi1 | NOVA l PBS

A teenager’s DNA was rewritten using a powerful new gene-editing tool. But what does prime editing really mean? Could this mark the beginning of a new era in medicine, or is it already at risk of disappearing? Why did the company behind it suddenly pull back? | The Brain Maze