You are in jail. Sentenced for life for a crime you didnt commit. You know the only way to prove yourself innocent is to escape jail and turn in the real criminal. The jail is minimum secruity and guarded by idiots so escaping shouldnt be a problem. Not much to it? The next map will be much more difficult...

Also try out http://www.planetminecraft.com/project/block-survival-challenge-1-chest/ My first map where you must survive on a giant storage chest block. Good luck!