"Walking on Thin Ice" is the ninth episode of Durarara!!x2 Ketsu and the sixty-second episode overall of the Durarara!! anime.
The Saika Army surrounding Russia Sushi continues to grow, and Erika Karisawa makes a risky bid for escape. Anri Sonohara setting off to find Celty Sturluson, the Blue Squares preparing to confront Chikage Rokujou forewarn confrontations to come, but the battle to the death between Izaya and Shizuo is already well underway.
adapted from what manga or LN chapter?
references to previous episodes?
In order of appearance (not including OP)