It's been about a month since Harry recieved a certain
letter. He'd pondered and contemplated what to do about it, and then ultimately forgot, for reasons that have a lot to do with microwaves, and Doritos, and small-scale destruction of inexpensive drugstore items, and fairy lore, and how not to make toast.
But we won't get into that.
Certain events, by which the Narrative means
mun stopped being a flake, led the Boy Who Lived to finally decide to do something about the note, sans
his royal entourage his posse his personal Redshirts Ron and Hermione, even though he knows they'd be a bit put off to think he'd gone to face a potentially deadly foe without anybody to stand in his way.
He leaves a note with Bar:
Dear "Vulpes",
I'm here if you are.
H...because really, what else does one SAY to an annonymous letter claiming to have information and then not explaining how to get it?
Harry orders a mug of butterbeer and takes a seat at a table.