Our Dirty Water

Nick Herringer claps along with a metronome. He draws lines on a big screen, repeating patterns drawn by the computer. He identifies icons of cars when they flash before his eyes. This is the 22-year-old's speech and cognitive therapy, which he has been doing at least twice a week. Every week. For three years.

Nick's thick brown hair hides a massive, ear-to-ear scar from his four brain surgeries for glioblastoma, an aggressive brain cancer he has battled since he was a teenager.

His mom, Tammy Herringer, drives Nick to therapy and back. She takes Nick along shopping and to community events. He...