TASK DEFINITION: Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.
PROBLEM: Christian Grey is a character in what recent book trilogy?

SOLUTION: christian grey

PROBLEM: What's missing: Magnum Force, The Enforcer, Sudden Impact, and The Dead Pool?

SOLUTION: sudden impact

PROBLEM: Who plays Captain Kirk in the 2013 Star Trek film?

SOLUTION:
star trek