What is an important change in one of the characters?John Steinbeck's Of Mice and Men

The old stable buck, Crooks, is a bitter and despairing
man who guards his terrible loneliness so that the barriers he sets in order to
retain his pride will not be broken.  When, therefore, Lennie naively ventures into the
barn to find his puppy to pet, Crooks defensively tells
Lennie,

"You
got no right to come in my room.  This here's my room.  Nobody got any right in here but
me."

But, Lennie does not
understand Crooks's insulting words.  And, when Crooks tells Lennie that he has a right
to have his light on in his room because he "ain't wanted in the bunk house," Lennie
innocently asks why Crooks is not wanted there.  With this innocent question, Crooks
begins to realize that Lennie is incapable of the racial hatred of the others; he
examines Lennie with his spectacles on.  When he yet scowls at Lennie, "Lennie's
disarming smile defeated him" and Crooks changes his tone, and he tells Lennie "you
might as well set down."

Still a mistrusting and wary of
Lennie, Crooks questions him about George.  Then, sensing that he can retaliate against
a white man by taking advantage of Lennie's childish mind, Crooks baits Lennie by
telling him that George may not return from town, and Lennie will be all alone.  But,
when Lennie becomes angry, insisting that he be told who has hurt George, Crooks backs
off and tells Lennie George is coming.  Still, he lingers with his racial retaliation,
"S'pose you couln't go into the bunk house and play rummy 'cause you was black.  How'd
you like that?"

Confiding in Lennie, however, Crooks
crosses the barriers he has set.  He tells Lennie of his terrible aloneness, of how he
"nothing to measure by" because there is no one with whom he lives.  Dreamily, Crooks
reminisces when he was a boy and lived a happier life. As Crooks talks with
Lennie, Lennie confides in him about his and George's dream, and Crooks "settled himself
more comfortably."  He then inquires about this dream, at first incredulously, but then
with some faith after old Candy appears and reiterates the plan, revealing to the stable
buck that he himself is involved and has money to put up for the ranch.  At this point,
Crooks becomes brave and drops all his social and racial
barriers,

He
hesitated.  "...if you..guys would want a hand to work for nothing--just his keep, why
I'd come an' lend a hand.  I ain't so crippled I can't work...if I want
to."

This openness on the
part of Crooks and his desire to share in the fraternity of men with Lennie, George, and
Candy demonstrates a rebirth of faith in mankind by Crooks, who has harbored resentlment
against white men for their treatment of him.  But, now, he asks to join them.  Surely
Crooks has let down his barriers of defense and taken a leap of
faith.