There is another universe, a lot like ours. Entrances to it are scattered throughout the world, in the places where the most psychological energy gathers. Schools, hospitals, that kind of place.
During any leap year, on February 28, this is the period of abnormal astral activity which opens the doors. At exactly midnight, the minute between the 28th and 29th, if you’re lucky or unlucky enough to be by one of these doors, it will open and beckon you. In this other universe, things are mostly the same, except all love and hate relationships are reversed. Your worst enemy is your lover, your best friend is out to kill you, that sort of thing.
It’s a nice head trip, a good escape from this reality. Have fun, but remember… if you enter, you are stuck there until next leap year.