One of Gotham's Deepest Secrets

Darkness had been entrenched here for a century.

The brick sewers of Gotham's old district were older than the city's history itself.

Those Victorian red bricks had once been the pride of municipal engineering, but now time and neglect had corroded them beyond recognition. The masonry had taken on a sickly dark red, like congealed blood, while moss and water stains spread across the surface in eerie patterns, like runes from some ancient ritual.

The air was heavy and damp, saturated with a complex smell.

Stale mold, rotting organic matter, chemical solvents left over from the industrial age, and some indescribable mineral scent belonging to the deep underground.

These odors layered over one another, fermenting for decades in the sealed space, forming a unique "atmosphere" that only Gotham's underworld possessed.

In an abandoned branch line near the eastern drain, a broad crack wound up along the brick wall like a scar in the structure. At its widest point, the crack was large enough to fit an adult's fist, and inside was a deeper darkness, gaps formed by displaced bricks leading into the soil behind the wall.

At the bottom of that crack, a puddle of viscous matter was slowly squirming.

It looked almost no different from the surrounding sludge: the same deep brown, nearly black color, the same wet, sticky texture, mixed with rotting leaves, insect remains, and unknown sediment. But on closer inspection, one would discover that the writhing of this "sludge" had a strange rhythm to it.

It was not being pushed by the current, but producing faint undulations from within, like the breathing of a sleeping beast.

This was Basil Karlo.

The citizens of Gotham knew him better by another name: Clayface.

Clayface was one of Batman's most iconic shapeshifting villains in the DC universe, famous for