If you're keeping up with the current season of Durarara!! x 2 then get ready for a break between this weeks 21st episode and the 22nd airing on September 12th. In case you're wondering what will be taking its place next week, it will end up being the 1st season's episode 12.5 OVA. Bellow is the tweet confirming the scheduled break and the airing of the OVA. It helps if you can read in Japanese or have a patient friend who is willing to translate for you.