Supermán #20

In "El enemigo invulnerable de Supermán," Superman races against time to stop a deadly bomb planted in Smallville, unaware that the criminal genius "Dragon" Lang has unleashed a robotic adversary—Ajax—designed to match his every power. With Lois Lane at his side and the clock ticking, the Man of Steel faces his most formidable challenge yet: a foe who is not just his equal, but seemingly invulnerable.

In a forgotten Martian cavern, Dr. Lewes and the Planeteers uncover ancient spaceships tended by dormant robots, their discovery unraveling a haunting message from a civilization banished beneath the planet's surface four million years ago. As Colonel Tommy Tomorrow, Captain Brent Wood, and Major Marty Miller stand on the edge of a lost history, the silence of Mars holds secrets that could change everything they thought they knew.