Sentence:  Now for these and other things (whereof I could tell a thousand) was the reckoning come that night; and not a line we missed of it; soon as our <WSD>bad blood</WSD> was up. I like not to tell of slaughter, though it might be of wolves and tigers; and that was a night of fire and slaughter, and of very long-harboured revenge. Enough that ere the daylight broke upon that wan March morning, the only Doones still left alive were the Counsellor and Carver. 
Meaning of the word marked with <WSD> tags:  A serious feud or long-standing grudge.