What happens in 'The Hobbit' when Bilbo meets the trolls?

the trolls capture all the dwarves but not Bilbo b/c he his smaller so he hides

then the trolls argue about what to do w/ the dwarves and how to eat them

then gandalf (who had left them a while ago) comes back and imitates the troll to keep them arguing until morning and they get turned to stone