Sentence:  One moment there was a man in the saddle ; the next a headless horror on a horse that bolted through the redcoat <WSD>ranks</WSD> , and during the next second or two , we all of us fired into the suddenly disorganized column of soldiers . 
Meaning of the word marked with <WSD> tags:  a row or line of people (especially soldiers or police) standing abreast of one another