When the Riddler escapes from Arkham Asylum, the Dynamic Duo discover he has a museum in his sites. But the Riddler's riddles reveal he doesn't just steal from the museum, he actually makes off with the whole thing! With the help of World War II-era decoding machines, the Riddler takes command of the Gotham City Military Museum--a fully-functional battleship! Now it's up to Batman and Robin spoil his plans before he blows Wayne Manor, and the rest of Gotham City, out of the water.
