What is the climax of William Sleator's novel The Beasties?

In William Sleator’s strange and creepy novel for young
readers titled The Beasties, a boy named Doug and his bookish
younger sister, Collette, accompany their father, who studies plants, on a trip to the
forest, where he plans to do research.  Logging companies have been stripping the forest
of trees, and strange creatures known as “beasties” have been retaliating by stripping
loggers and other humans of various body parts. Doug and Collette eventually become
friendly with the beasties, including one, named Fingers, who has no
sight.

When the Queen of the beasties dies, a new queen is
needed.  Fingers is willing to take on the role, but her blindness seems an insuperable
obstacle.  As she explains to Doug in the strange dialect she uses, the beasties “never
pick Queen who can’t see.” When Doug suggests that eyes might be taken from the most
recently dead humans in the forest, Fingers replies, “Cannot taking parts from dead –
can only do it if taking minutes after they die.” The corpses, then, are not available
sources of the needed eye or eyes. Nor can eyes be donated (Fingers explains) by other
beasties.

Doug, worried that without a new queen the
beasties will go extinct, eventually arrives at a solution that shocks both Fingers and
Collette:

“You
will be able to see, Fingers,” I said, “because I’m giving you an
eye.”

Surely this statement,
which comes at the very end of chapter 14, is one of the most important climaxes in the
book, if not the most important climax of all. It suggests a kind of climax to Doug’s
moral growth, symbolizing his willingness to sacrifice his own best interests on behalf
of another.  Fingers is deeply touched, and although Collette raises objections, Doug
quickly silences them, even though he realizes that with just one good eye left, his
skills as a baseball player will be greatly diminished. When Fingers asks whether he is
serious, Doug responds almost angrily that he is and makes it clear that the decision is
voluntary and is his alone.  Doug’s decision is a startling climax to the narrative that
has preceded this crucial moment.