BOISE -- When Justin Skeesuck saw a documentary about the Camino De Santiago, a 500-mile pilgrimage across Spain, he had only one thought.

"You come across something that you very instinctly know it's what you need to do," said Skeesuck

A neuromuscular disease caused Justin to lose the ability to use his arms and legs, so he knew he was going to need some help. So, he asked his best friend, Patrick Gray.

"He just turned to me and asked me, 'so do you want to go across 500 miles in Spain with me?' And I said 'yeah, I’ll push you,'” said Gray.

MORE: Meridian men prep for journey of a lifetime

After more than a year of preparation, the Meridian pair flew to Spain in 2014 and hit the trail. The trek was extremely challenging, but 35 days later they made it across all 500 miles. Patrick pushed Justin every step of the way.

"You just do that day in and day out, by the time you are done you're tired," said Skeesuck.

Three years later, the pair is now finishing another long journey. After 18 months of work, Patrick and Justin are releasing a book detailing their journey. Fittingly, it's called “I’ll Push You.”

"We just want to be able to share our message," said Skeesuck.

The pair says writing a book really wasn't part of the plan, but after being asked over and over if they would, they finally gave in.

"I think our goal with this book and the film is to shed light that you can achieve more together and in a community, the Boise community from the get go has been in our court," said Skeesuck.

RELATED: I'll Push You: Meridian friends complete Camino de Santiago

Just like their journey across Spain, the creation of the book revolved around teamwork.

"He got the written word out and I helped with the creative direction,” said Skeesuck.

“We both got it out, it was fun," laughs Gray.

The book dives not only into their journey, but a friendship that spans over 40 years

"We went all in, we didn't hold anything back," Skeesuck said. "It's raw, and it's hard, it's also funny and stupid... and everything in between," said Skeesuck.

Part of the duo's goal was to say thank you to the Treasure Valley.

"To say, 'yeah, because of you, this is what we experienced and now we are able to come back and share those experiences with the community that supported us,'" said Skeesuck.

PREVIOUS: Meridian duo finish incredible journey

"On a whole we just love being able to work together and share our stories and meet people from all around the world, it's really fun," said Gray.

Now that the book is out, Justin and Patrick are looking forward to their next journey

"We have a few ideas in the hopper," Skeesuck laughed. "I can tell you, it will not involve mountains."

The pair will be holding a free talk about their journey and a book signing at the Barnes and Noble on Milwaukee Street in Boise on Thursday, June 17 at 7 p.m.

For more info on their journey and new book, click here.