Joshua was John Winchester's first sergeant in the Marine
Corp, and he was a true blue Marine. The mannerisms and
discipline he learned in the Corp carry over even now that he
is retired. He considered being a Marine the most honorable
thing that a person could do for their country, and instilled that
into young John Winchester.
He retired from the Marine Corp after suffering a near
breakdown. He saw something he couldn't explain, and things
he couldn't explain kept happening. He soon learned he
wasn't crazy, there were things in the world that normal people
refused to see. The blinders were ripped off Joshua's eyes,
and he became a hunter, using his Marine training as a guide.
He and John Winchester reconnected a few years after Mary's
death, and Joshua took John under his wing, as he had years
before, and helped teach John the ways and hows of hunting.
Now, he finds himself caught up in the Winchesters' lives once
more, this time with John's sons in a battle he never imagined.