Wondering why Sue Sylvester looks as though she has just seen a ghost? Well, keep wondering! Because this TV Addict is not about to spoil tomorrow night’s episode of GLEE that features special guest stars Molly Shannon and Olivia Newton-John. Except to say that said look of horror plastered across Sue’s face may have a little something to do with a video gone viral. More first look photos of which — including an equally mortified Rachel Berry for reasons unrelated — can be found after the jump.