“I know some of you saw me on my phone when I walked out,” Trent Reznor told the crowd at Saturday’s Nine Inch Nails show at the Hard Rock Hotel & Casino in Las Vegas. What happened next is one of the most touching things we’ve ever seen.

Let’s rewind a little: Andrew Youssef is a photojournalist. He’s spent seven years taking pictures of musicians ranging from Black Sabbath to Depeche Mode. Nine Inch Nails is one of his favorite bands.

Get push notifications with news, features and more.

In 2011, Youssef was diagnosed with stage four colon cancer. He continued shooting bands, and has written about his struggle in a recurring OC Weekly column called “Last Shot.” Throughout his battle with the disease, he continued to seek comfort in Nine Inch Nails’ music, seeing them live whenever he could.

Reznor, the man behind NIN, started following Youssef on Twitter in August. He invited him to a show, and started spending time with him every day while the band was in town rehearsing for September shows at LA’s Sports Arena. They ate lunch, talked about Breaking Bad, and became friends.

Recently, though, Youssef had to give up his concert attendance schedule per his doctor’s orders, and scheduled his last two NIN shows: Nov. 8 in LA, and Nov 16 in Las Vegas. Sadly, his health wouldn’t permit him to make the latter.

Which brings us to Nov 16. Mid-conert, Reznor pulled out his iPhone, and dialed up Youssef on FaceTime. “Andrew. What’s up, man?” Reznor says. “I got some friends I want you to meet.” He holds the phone up to the crowd, asking “Can you guys say ‘hi’ to Andrew?” The crowd chants Andrew’s name, and Reznor says, “Just wanted to tell you I miss you, man, and I wish you were here,” before the band launches into “In This Twilight,” a song Youssef had titled one of his most wrenching posts after.