By the time Marley realized there was an infiltrator in their port, Armin had already transformed into the Colossal Titan, vaporizing the Marleyan navy and cutting off any hope of reinforcement for the soldiers in Liberio. ⚡ Summary of Tactics

Beyond raw data, the mission sought to understand the "humanity" of the enemy. In a poignant parallel to the Scouts’ own past, Eren Yeager—who joined the mission under a fake identity—witnessed the Festival of the Liberio Internment Zone. He saw Eldians in cages, forced to wear armbands, and children being indoctrinated to hate their own heritage. Through the eyes of the Scouts, the narrative reframes the conflict. The enemy is not a monolithic evil; they are a society drowning in fear and historical grievance. This realization shattered the simplistic "us vs. them" mentality. However, it also hardened Eren’s resolve. While Armin Arlert marveled at the sea’s beauty and the irony of a shared world, Eren saw the "other side of the ocean" as an enemy that wanted his home erased. The undercover mission, therefore, served as the catalyst for the series’ central ideological fracture: the conflict between negotiation (Armin/Hange) and preemptive annihilation (Eren).

If you'd like to dive deeper into this specific arc, let me know: Should I focus on the battle details?

This plotline allows for significant character development, particularly for the scouts, as they face challenges and make tough decisions in a foreign and hostile environment. The interactions between characters, both within the scout group and with Marleyans, add depth to the story.

The climax of the undercover effort was not a quiet retreat but the Liberio Raid. Having gathered enough intelligence, the Scouts facilitated Eren’s attack on the Marleyan military festival. This act was a strategic gambit to cripple Marley’s command structure and devour the War Hammer Titan, but it was also a moral point of no return. By infiltrating Marley and then striking its civilian district, the Scouts committed an act of terror from Marley’s perspective. They transformed from underdogs into global aggressors. The mission’s tragic irony is that the Scouts succeeded too well. They brought back the information needed to save Paradis, but in doing so, they lost their moral clarity. The mission fractured the corps: Levi remained a soldier focused on survival, Hange was tormented by the ethics of the raid, and Eren became the very monster the world feared.

The Scouts used a stolen Marleyan airship as a mobile extraction point, allowing them to vanish as quickly as they appeared.

Dressed in civilian Marleyan trench coats and hats to obscure their faces and Omni-Directional Mobility (ODM) gear.

They wore the mandatory armbands required for Eldians in Marley to avoid suspicion from the Marleyan Public Security authorities.