Instructions:
The object is to collect points by hiding a special item in one of your rooms, so that 5 of your friends can't find it, and to find the item from 15 of your friend's rooms. This mission is on when you see the "Hide&Seek" icon on bottom right side of your gamescreen.
First, go to the room where you want to hide the item. Edit the room, and you'll find a hideable carbuncle from your inventory. Notice that this item goes behind all the other items, so it's not for decorating.
After you have hidden it and saved the room, "challenge" your friends so that they can try to find it!
Clicking the 'Hide&Seek' icon on bottom of the gamescreen again opens the box with information of your progress. You can visit your friends who have hidden the carbuncle through this box, or through the feed-posts on your Facebook wall. When you search for it from your friend's place, you can move any items there. No worries though, the room doesn't actually get edited during this and will be normal for other visitors and for your friend. Be quick, you only have 15 seconds to turn the room around!
Once you've completed the mission (succesfully hidden the item from 5 friends, and found the item from 15 of your friend's rooms), you'll get a carbuncle in a cage to yourself to keep, and this time it will be for decorating.
Happy Hunting!