Suprise EB Guest

So my latest edition of the Empty Bottle Show List email tells me there's a show coming up on Oct. 11 with a special surprise guest. In fact, you may have to buy the tickets and show up without knowing who that guest is. Per the email:

Also, you'll find it curious that we've got a 'special surprise guest' playing here on Thursday, October 11th. We may or may not be disclosing the identity of said group, but we can tell you that the show would sell out in minutes if and when we announce them. You adventurous types may want to hedge your bets and buy a ticket now, assuring yourselves the opportunity to see some old friends play a late night set.

Hmmmm, old friends . . . how very cryptic.