Darius Weems is on a mission, but even though he is only 23 years old, it's a race against time.
Darius, an aspiring rapper and star of the documentary, "Darius Goes West," suffers from Duchenne Muscular Dystrophy, a rare genetic disorder that results in the disintegration of muscle tissue. Legs and arms are seized, and eventually, so are the muscles that surround the heart. In the United States, the majority of people afflicted with this disease die by age 25.
For Darius, the disease has been a slow but steady progression. He could walk when he was little, but was then diagnosed with DMD around age 5. By age 9, Darius transitioned to a walker and then to a wheelchair at age 12, where he has remained for the past 11 years. Today, he can only wiggle his fingers and feet, but there is so much more he wants to do, like make music and find a cure for the disease that took his brother at age 19.
"In my situation, I would say I'm blessed," he said. "I can still brush my teeth and stuff."
He knows there may well be a day when he can't, but Darius said he doesn't see life like that.
In addition to raising money for DMD research, Darius is also a research subject. A patient at the Kennedy Krieger Institute in Baltimore, Darius is taking part in a clinical trial, designed to help cure the disease.
"As long as I'm here and being able to motivate people and being strong for them, hey, I'm living my life to the fullest," he said.
His hope is placed squarely on a clinical trial being run by Dr. Kathryn Wagner and Dr. Daniel Judge. The Kennedy Krieger Institute research team has collaborated with the Division of Cardiology in the Johns Hopkins University School of Medicine, to discover whether sildenafil, the active ingredient in Viagra, will help stimulate deteriorating muscles, especially around the hearts of Duchenne patients.
When faced with his odds of survival, Darius admitted he feels down sometimes, but that he is trying to live one day at a time.
"Just because I have a fatal disease doesn't mean any doctor can put any amount of time on my life," he said. "But you know, I think about the situation that is at hand, trying to cure this disease and trying to carry on my brother's legacy, and you know losing him kind of made me want to get out here and show people how fatal this disease is and how big of a problem it is."
We first met Darius back in 2007 when then-"Nightline" anchor Martin Bashir spent some time with 17-year-old Darius. Bashir had a particular interest in Darius' story because his own brother had died of DMD.
At age 15, Darius had taken an extraordinary journey across the United States in a van built to accommodate his wheelchair.
"I'm in a wheelchair but I'm just like a regular person," he said in 2005. "Never think I'm like somebody else. I'm just the same as other people. I've got talents."
The idea to travel across the country was Logan Smalley's. Logan had been a counselor at a camp where he had met Darius' brother, Mario. When Mario was dying he asked Logan to keep an eye on Darius. Logan promised he would and he took that promise seriously.
The California trip began as a bit of a lark. MTV's "Pimp My Ride" was popular, so Logan joked that maybe if they could get Darius from his home in Athens, Ga., to California, West Coast Customs, the company featured on the show, would "pimp" his wheelchair.
"I was definitely excited about the whole thing," Darius said. "But one thing that came to mind was how are we going to get the money for this, you know, how are we doing to convince our parents to let us go on this road trip."
But they did, and the trip became a documentary, "Dairus Goes West," which Logan directed and produced. Even though West Coast Customs refused to "pimp" Darius' wheelchair, the journey was a stunning success. The documentary is partly a coming of age story and partly a story of friendship and gratitude.
"He'll motivate me to do something that I never thought I would do," Darius said of Smalley. "Him actually taking on the goal of watching over me when my brother passed away, so he definitely gave me a lot of hope and being that brother when I lost my brother."
Dairus and his friends traveled to the Grand Canyon, where the view brought tears to his eyes, and to the Pacific Ocean, where Darius stood on his own for the first time in almost four years.
The power of the film is drawn from Darius and Smalley's incredible friendship and their belief in one another. The tale of two young men, who couldn't be more different on the outside or more alike on the inside.
"I think that Darius and I have a mutual respect for each other," Smalley said. "It's just like some strange mixture of brotherhood, parenthood, old married couple, best friends, like our relationship runs the gambit. I love him more than anybody and we just have so much fun together and it feels really good because it feels like we are making a difference."
Though the years, Darius and Logan have given each other a lot of laughs. One of the most poignant moments in the film happened by accident. While visiting the San Francisco Zoo, Logan and the other guys on the trip dared him to eat a spoonful of super-spicy wasabi, something he had never heard of before. He took the challenge and immediately started spitting as his friends collapsed into giggles. And that is part of the film's message: despite his illness, Darius is just one of the guys.
"When we were filming and we were all in the restaurant, and there was a lady by us and she thought they were picking on me and stuff like that," Darius said. "[But] it shows a good message and they are treating me like others."
It is that scene perhaps, more than any other in the documentary, that captivates the kids in the schools Darius and his friends now visit to talk about his journey. His story has become a popular way to raise money for medical research for DMD.
"Some schools from time to time do the wasabi challenge," Darius said. "I don't know how they ate the spoonful of wasabi like that. It's crazy, know what I mean, seeing people motivated enough and being brave enough to take a spoonful of wasabi."
So far, Darius has raised more than $2 million for the cause, much of it to the sound of laughter.