Two years ago, this story would have been science fiction.  

Kelly Thomas, 24, who is paralyzed from the chest down, pulls herself up to standing, takes one step, moves her walker a little bit ahead of her, and then takes another step.

Jeff Marquis, 35, whose legs, feet and hands are paralyzed, winces as he pulls himself up to stand, the gingerly steps forward. 

The gaggle of people around them gasp. 

'Eventually I want to get rid of the walker and get faster,' Thomas says. 'I think that's gonna come with just walking more and more.'

Astonishingly, she's right.  

Thomas and Marquis are two of just three paralyzed patients who can walk again thanks to a device implanted in their spines and intense physical therapy.