Excuses Wanted

Here's a turn up for the books - get text from Little Hippy Mate as she's going to be opening her tattoo and piercing emporium and will be having a party and I'm invited plus a guest (not of course that I can think of anyone to take with me). Now forgive me for being Mister Cynical here but as I only ever seem to hear from her when she wants something like a shop measuring I'm not exactly thinking that this is extending the hand of friendship, I'm wondering what she wants.
The other thing is that I can't help but feel that some of the cast of The Really Scary Circus will be there and I just don't want to see them again, in my view never would be too soon and to be perfectly honest I don't really think I'd be able to remain civil with them and I don't want to cause too much of a fracas.
So there we are the problem is: invite for two but no one to make up two with, people with whom a state of war exists, vague possibility of picking up a bit of photo work. So how on earth do you manage the situation? Appear briefly, have one drink and a canape, make excuses and fuck off, apologise for non-attendance at short notice or go and do something completely different whilst ignoring the whole affair? I really could do with some helpful advice on this one.