Aquaman in "And Death Before Dishonor"
The Ocean Master forces Aquaman to go to Atlantis to get Serum X, which can transform air-breathing humans into water-breathers. When he arrives in Atlantis he is informed that Karshon is now ruler, and Karshon refuses to give him Serum X. He attempts to steal the serum and is attacked by Karshon and his pet shark. Aquaman decides to leave with out the serum, and with the help of the creatures of the sea defeats the Ocean Master. Later Mera informs Aquaman that he has been falsely accused of stealing Serum X, and Aquaman vows to find out who framed him.
Aquaman in "Aquafamily"