Across the River
Game Fire Emblem: Thracia 776 Objective Seize Gate Units Allowed 8 Units Gained - Boss Reinhardt Saias Cowen

“Leaf led his troops and pushed on past Fort Danzhi towards Manster. Now, the only obstacle that lay between them and Manster was the Great River of Thracia, the widest and longest river on the Thracian Peninsula. With its mineral-rich water, this river was the source of prosperity for the cities in Northern Thracia. Once this river was crossed, Manster would only be a few days away.”
—Opening Narration

Across the River is Chapter 22 of Fire Emblem: Thracia 776.