A British real-life Forrest Gump is more than 600 miles into a 6,000-mile coast-to-coast run across the US dressed as a superhero.
Jamie McDonald, 31, has just crossed the border into California, the third of 15 states the adventurer will run through.
The former tennis coach, from Gloucester, started his feat in April at Cape Alava in Washington, the most western point of the US.
Running by himself with no support crew, Mr McDonald will battle through desolate and lonely deserts, sub-zero temperatures and the constant threat of wild animals, injuries and the uncertain elements as he runs the equivalent of 230 marathons.
He has previously run across Canada dressed as superhero The Flash and this time he is running as his alter ego, Adventureman.
Mr McDonald, who is in a relationship with fellow adventurer Anna McNuff, said: "I've been through so much already, and I'm only just into my third of 15 states - and it's an enormous one.
"It being huge, though, gives us huge donation and support potential, so I'm hoping the extra miles will make a bigger difference.
"At the beginning of this run, just days in, I injured my foot so badly that I thought I'd have to start again.
"Through careful management and lots of barefoot running, I've hit more than 600 miles - around a tenth of the total distance I'll need to run - in around 40 days.
"My maths isn't great, but that tells me that I have a good shot at making it before my visa runs out."
Mr McDonald, who suffered from debilitating immune deficiency and the potentially fatal spinal condition syringomyelia as a child, spent the first nine years of his life in and out of children's hospitals and is hoping to raise £250,000 for the Superhero Foundation, a charity he co-founded.
"I'm feeling confident, but I do have days where I sometimes think I might not make it. I'm running 20-mile days most days, and I'm running like I've got the wind at my back," he said.
"I might only have just started in the grand scheme of the adventure, but I'm into my stride and nothing's going to break me.
"I'm doing this to show people, and especially children in situations like I was in, and many worse, that anything is possible, and that you can't give up on hope and health.
"I'd like to thank the US so far for taking me in when I've most needed it - I couldn't do this without the kindness of people."
Mr McDonald came to prominence in 2012 when he cycled 14,000 miles from Bangkok to Gloucester on a £50 second-hand bike.
Just weeks after returning to Gloucester, he set a new world record for cycling non-stop on a static bike. In February 2013, two months after setting the new world record, he began his run across Canada.