in the Otherland
series by Tad Williams
. Orlando is a 14-year old boy with the rapid-aging disease progeria
and exceptional skills on the 'Net, both with hacking and gaming.
It is in the VR MMORPG Middle Country, in his barbarian character Thargor, that he first glimpses the Otherland network. He devotes what is left of his quickly fading life to finding out what he saw. Along with his friend Sam Fredricks and his software agent Beezle Bug, he scours the 'Net to find any clues.