Here's the idea: You will be given a letter of the alphabet. You must choose three heroes whose names begin with that letter, and describe the mission these three heroes will fulfill. Then, choose another letter.
Example: B
Heroes: Bond (James), Beowulf, Bouncing Boy
Mission: The three heroes must join forces to stop a time-traveling madman from destroying the universe.
Heroes may be from any genre. First, last, and code names are all acceptable.
Clear enough?
Let's start with the letter S.