'Chaos is a ladder' - Game of Thrones season 7 episode 4: Bran's line to Littlefinger explained

The significance of his solemn statement

*Spoilers ahead for Game of Thrones season 7 episode 4, 'The Spoils of War'*

A deft little scene between Ser Petyr Baelish and Brandon Stark/The Three-Eyed Raven came to a curious conclusion you can be forgiven for not understanding the impact of this week, involving a reference that links back to season 3.

Littlefinger was up to his usual 'you can count on me I'm a straight shooter' schtick in Winterfell, sympathising with Bran: "I imagine you've seen things most men wouldn't believe. To go through all of that and make your way home again only to find such chaos in the world, I can hardly imagine - "

He was cut short by Bran, who said blankly: "Chaos is a ladder."

Bran was quoting Baelish himself, who had the following exchange with Varys in season 3 episode 6, 'The Climb':

Petyr 'Littlefinger' Baelish: The realm. Do you know what the realm is? It's the thousand blades of Aegon's enemies, a story we agree to tell each other over and over, until we forget that it's a lie.

Lord Varys: But what do we have left, once we abandon the lie? Chaos? A gaping pit waiting to swallow us all.

Petyr 'Littlefinger' Baelish: Chaos isn't a pit. Chaos is a ladder. Many who try to climb it fail and never get to try again. The fall breaks them. And some, are given a chance to climb. They refuse, they cling to the realm or the gods or love. Illusions. Only the ladder is real. The climb is all there is.

So why did Bran choose to repeat this assertion to repeat?

He was basically letting Littlefinger know he is wise to his games. Bran has seen literally everything in the Seven Kingdoms, including Littlefinger describing his philosophy of manipulation at a time when he was allied to the evil Joffrey. Bran presumably knows Littlefinger played a role in his father Ned's death, and it might have just placed him on Arya's kill list.

Bealish has had little luck deceiving the Starks so far this season, also having run-ins with Jon and Sansa over his silver tongue.

Game of Thrones continues on Sunday nights on HBO, Sky Atlantic and NOWTV.