stinger
n.n. a sharp, pointed object that can cause a lot of pain, like a bee's needle or a knife. In a more modern sense, it can also mean a powerful ending to a story or a movie that leaves a strong impression.
n. a sharp, pointed instrument or appendage used for piercing or injecting venom. In a figurative sense, it refers to a powerful, memorable conclusion to a narrative or performance.
The bee's stinger is very painful if it gets you.
The documentary ends with a powerful stinger that shows the impact of the policy on local families.
The director used a clever stinger at the end of the film to tie the protagonist's personal journey back to the central mystery of the plot.
From sting + -er. Both figurative and literal senses appeared in the 16th century.