Having arrived at the Ōkeanos, Odysseus and his companions beach their ship there and disembark, Ο.11.020, proceeding to the place in Hādēs where Circe had instructed them to make sacrifice to the dead, Ο.11.021–022. To get there, they go along the streams of the Ōkeanos, O.11.021. It is not said explicitly here that they have crossed the Ōkeanos in order to make their entrance into Hādēs, though the crossing is made explicit in the instructions of Circe at O.10.508. See the comment on O.10.508–512. Nor is it said that they will cross the Ōkeanos when they finally make their exit from Hādēs, O.11.636–640. When they do make their exit, Odysseus and his companions are pictured as reembarking on their ship and navigating it in the streams of the Ōkeanos, O.11.639–640, heading back to the sea that will take them back to the island of Circe. Then, at O.12.001–003, when they finally reach the sea again, from where they will navigate back to the island of Circe, this island is situated no longer in the Extreme West but in the Extreme East, O.12.003–004. So, by implication, they will have navigated all the way around the world by way of the Ōkeanos, from the Extreme West all the way to the Extreme East. This circumnavigation ends up at the same place where it started, at the island of Circe, but now this island is situated not in the Extreme West but in the Extreme East. So, the location of Aiaia, this island of Circe, is a coincidence of opposites. The achievement of such a coincidence by way of the Ōkeanos can be imagined as either a looping around the world or, better, a looping under the world: either way, the circular cosmic river Ōkeanos flows from West to East to West to East and so on forever. For more on coincidences of opposites, see the comments at I.01.423–425 and at O.01.022–026, O.10.135.