The callbacks to small details from the show’s opening continue to dominate season seven.
In season one, the assassination attempt on Bran, and the subsequent suspicion Littlefinger places on Tyrion Lannister for being behind the attempt, helps trigger the war between House Stark and House Lannister, which was likely Littlefinger’s aim. (Chaos, after all, is a ladder that provides opportunities for ambitious men, as Littlefinder once told Varys — a quote Bran throws back in his face, as a hint that he’s seen more of Littlefinger’s behavior than any double-dealing schemer could want.) While the show hasn’t explored who’s truly behind the assassination attempt, in George R.R. Martin’s novels, Tyrion later hypothesizes that Joffrey was behind the assassination attempt, for some fairly elaborate and not entirely convincing reasons. Since Joffrey and Catelyn are already dead, it’s unlikely the show will revisit this exact tidbit. However, Littlefinger does openly tells Bran he doesn’t know who the dagger belonged to before the assassination attempt, opening up the possibility of different revelations about who may have had involved in the attempt on Bran’s life.