They passed Peeves near the turning into Gryffindor Tower, but he was streaking happily toward the source of the yelling, cackling and calling, When there’s strife and when there’s trouble Call on Peevsie, he’ll make double!
There are no more uses of "strife" in the book.
Show samples from other sources
Call it the circle of strife: The Arkansas couple who drove it before me were sketchy; Ozark Amy was obviously shady; hopefully, some Illinois down-and-outer will enjoy it for a bit too.
Gillian Flynn -- Gone Girl
I hear things, rumblings in Downworld, the rumor of coming strife.