Players of Happy Island have the next 3 days to unlock the Box of the Unknown. Cracking the box open requires publishing 6 posts on one's Facebook Wall, corresponding to the 6 locks on the box. Once opened, rescuers will be treated to an exclusive animal for their island.
An easier way to bypass the locks is to cough up 599 Facebook Credits to use the "Hire a Locksmith" option, which is nearly $60 USD! The only way that's a reasonable price is if you had every intention to pay ten bucks per friend to click on your Wall Posts.