Aquaman takes on the country that attacked Poseidonis, discovering a truth about his old city that he may not be ready to face.
The second attack on Poseidonis has left the city in ruins and Aquaman out cold. With the help of the sea creatures, Aquaman turns back the attacking submarines of Oumland. In his attempt to stop the onslaught with a visit to Oumland, does he cause more harm than good? And what is this new threat to the city?