cliffhanger

from WordNet (r) 3.0 (2006)

cliffhanger
    n 1: a contest whose outcome is uncertain up to the very end
    2: an episode that ends in suspense

from The Collaborative International Dictionary of English v.0.48

cliffhanger \cliffhanger\ n.
   a contest whose outcome is uncertain up to the very end.
   [WordNet 1.5]

   2. an episode of a drama that ends in suspense.
      [WordNet 1.5]