Akanishta Heavenly Dao Palace.
A perfectly square black cube towered over the ground.
Its pitch-black walls reflected a dull metallic sheen, shrouding the entire area around the cube in an impenetrable darkness that swallowed all light.
And for some reason, staring at the enormous black cube for too long gave one the terrifying sense that it might come alive.
It seemed less like a cold, lifeless lump of metal than a living beast of steel.
This was the prison on the eighth floor of the Heavenly Dao Palace, known as the Black Tower.
Now, the scrape of dragging chains mingled with slow, heavy footsteps in the spacious corridor inside.
Just like its cubic exterior, every room within was a perfectly proportioned cube.
The entire prison looked like a loose arrangement of countless cubes, yet they were all tightly interconnected, inseparable.
At the sound of chains and footsteps striking the floor, a commotion immediately broke out in the previously quiet cubic cells on either side.
Pairs of eyes peered through the iron bars toward the corridor.
Those gazes brimmed with mockery and delight at someone else's misfortune.
As far as they were concerned, another unlucky soul from who knew where had been thrown into prison.
Ever since they had been transferred here from the underground chambers of the General's Residence, a sizable batch of newcomers had arrived every year.
"What rotten luck. I wonder which village's ninjas they've brought in this time."
"Well then, let's take bets. I'll put up a pack of cigarettes. I bet Konoha has the most ninjas among this batch!"
"Get lost. I bet Hidden Cloud has the most. The Land of Night has the deepest grudge against Hidden Cloud! They'll try anything to uncover this place's secrets!"
The prisoners had long since grown accustomed to finding