What is the moment of climax in Rosencrantz and Guildenstern are Dead?I am looking for the most dramatic question in this play. and I have been...

I think the most dramatic question in the play comes near
the very end.  Rosencrantz and Guildenstern know that the letter they carry is the death
sentence of their friend Hamlet, but they do nothing to stop those events from going
forward.  They are willing going head with Claudius's plan.  Even more shocking is when
they re-read the letter later to discover that Hamlet has re-written it to say that the
bearers of the letter, Rosencrantz and Guildenstern be "put to sudden death."  They are
shocked!  Guildenstern says, "But why?  Was it all for this?  Who are we
that so much should converge on our little deaths?  Who are
we?The player responds, "You are Rosencrantz and
Guildenstern.  That is enough."  This conversation nearly sums up the entire play. 
These two men have spent the whole play waiting to be told what to do and take no
definitive action in making their own choices.  They are existentially dead.  That, in
addition to the fact that the author is ultimately "in charge" of a text, is the whole
point.  This whole DOES depend on them.  Stoppard couldn't tell his story without his
creation of these characters.  Everything in this play does come to
a head when they "fail to reappear" on the last page, and we are transported back to the
allusion play, Hamlet.