One can tell a cafe is going to be at least a little peculiar when entering it requires ringing a doorbell and being scrutinised through the door hole by an employee. The strange sentry would lean over and take a confirmatory sniff before letting each guest, if confirmed to be not a threat, pass with a nod. From there, short flight of steps leads down into the darkness. Already, it should be obvious that this place wasn't just a cafe. It was a hideout.
At the bottom of the steps, is another door - an unguarded and, arguably, friendlier one. Sure it's yet another metal door, but unlike the outer entrance it wasn't featureless. There were two simple laminated signs attached onto the door. One simply said "Open!" and the other said "Welcome to Bloodclot Cafe!" in big bold letters with "Open: 8pm -6am" in smaller font.
Open the door and one would be greeted by a remarkably ordinary cafe interior furnished with cozy armchairs, wooden barstools, and coffee tables of polished oak. Anyone who had been shown an image of the cafe interior by itself, wouldn't have guessed that this place was, in fact, an establishment for bloodsucking creatures of the night.
At least not until one notices the complete lack of windows or the menu board on the wall. Or the more telling vampiric features of some of the staff and customers. But aside from that, this is but a normal cafe. Don't mind the vaguely metallic scent wafting from warm cups of deep red. Or the fact that the cafe is apparently offering student discounts on puppy blood.
Just take a seat. Have a drink.
And, again, welcome to Bloodclot Cafe.