On the night of Thursday 22nd June, at 2300, there will be a minigame requiring you to kill the Umpire.
If you can find and kill the umpire in the area below between 2300 and 0000 then you will get a points bonus. The entire area will be in bounds for assassins, but with some special rules in force.
The area is detailed below:
ie all the grassy bits and the Fen Causway where adjoins such. I suggest people are wary of ambush while apporaching the area.