Sentence:  Old Order , acted and atonally sung by Grunnfeu Arapacis , the lovely Serbantian import , <WSD>then</WSD> entered and delivered the well-known invocation to the god Phineoppus , whereupon the stage is quite unexpectedly visited by a company of wandering Gorshek priests , symbolizing Love , Lust , Prudence and General Motors , respectively . 
Meaning of the word marked with <WSD> tags:  at that time