We actually progress in the story now! I don't know if I'm just dumb or what (probably just dumb) but I didn't see the "coup d'etat" coming. I was looking at a "Mess with the Survey Corp and we'll unleash Titan Eren" plan from Erwin but it they took the hard way and just waged war with the King.
Previously on: Attack on Titan 53: Eren tried to do "Hardening" but failed. Eren had a vision of a lady who looks like a mix of him and Historia, he forgot about it immediately as if it were a memory that does not want to be remembered. Erwin and Nile talk about who the mastermind for the attempted kidnappings for Eren and Historia is/are. Lastly, attempts to capture Eren and Historia have failed due to Survey Corps' tactics and strategies. They used their enemies' attempt to capture both to infiltrate their headquarters. Jean and Armin were disguised as Eren and Historia to be baits for the enemy. We end with the Survey Corps getting ready to rescue Armin and Jean.
Spoiler Alert! If you are gonna read this post, please read the actual manga first!