Aquaman 1st Series #11 (1963 DC) 1st Appearance of Mera - KEY ISSUE Aqua Lad

This issue features the first appearance of the character Mera, who would become a long-standing partner and eventually wife of Aquaman. The main story is titled "The Doom from Dimension Aqua!". The plot involves Mera, the exiled queen of a watery dimension, enlisting the help of Aquaman and Aqualad to fight the criminal Leron, who has seized control of her kingdom. Aquaman discovers that lead can neutralize the hard-water powers of the invaders, helping him defeat Leron and inviting Mera to stay in Atlantis.