Sentence:  When Timothy and Julia hurried up the staircase to the bedroom floor, where a considerable commotion was taking place, Tim took Barry Leach with him. [...]. The captive made no resistance and came not only quietly but in a <WSD>series</WSD> of eager little rushes like a timid dog on a choke chain. 
Meaning of the word marked with <WSD> tags:  A number of things that follow on one after the other or are connected one after the other.