When: 31 October, after the feast -- 1 November, dawn.
Where: Room of Requirement.
Rating: There is alcohol. We'll see.
Summary: It's a Halloween party. Whatever.
The Room of Requirement is located on the seventh floor, opposite a tapestry showing Barnabas the Barmy trying to teach trolls to dance the ballet. To make the Room appear, a person has to walk past the section of blank wall three times concentrating hard on what is needed.
What is needed, of course, is a party.
The official feast had a thousand live bats and pumpkins large as garden sheds, but Seamus And Dean's Brilliant Halloween Extravaganza was not quite that amazing. Since it was in the Room of Requirement, though, it was amazing enough. And they'd more than made up for the lack of live bats with the black-market Butterbeer and Guinness.
Let's get this party started.