Creatures of the sea are acting in strange and aggressive ways lately. It turns out Lex Luthor is undergoing an unethical, underwater experiment and has also imprisoned the legendary Aquaman. Lois and Clark must help Aquaman before a war breaks out between Earth and the City of Atlantis.

Ra's al Ghul and his Society of Shadows arrive in Metropolis to steal a mythical staff currently on exhibit. The staff can be used to steal Superman's powers and transfer them to Ra's. It is up to Batman to locate and rescue Superman from the immortal foe.