Black Bolt, the monarch of the Inhumans, is one of marvel's deadliest superheroes thanks to his extremely destructive voice. He can harness electrons with a whisper, and use them to turn the smallest word into a weapon of mass destruction. Despite this ability and his enhanced Terrigen-mutated body, there was one jail even he struggled to escape from; a prison where the warden's mind games sapped his resolve, disabled his powers, and chipped away at his Inhuman mental fortitude. To escape, Black Bolt had to rely on help from a surprising list of friends motivated by super-powered compassion.
The Prison uncovered The Midnight King's emotional vulnerability but also revealed the compassionate side of one surprising supervillain. Along with enforcing cruel punishment on criminal inmates, the Jailer also incarcerated and terrorized super-powered children; this depravity ran deep enough to penetrate Absorbing Man's conscience. He plotted an escape with Black Bolt, along with an intriguing cast of characters from around the cosmos. In the end, Absorbing Man decided to forgo freedom in order to get the gang to safety. In so doing, he forfeited a future with his lover, Titania. The Prison and its jailer proved terrible enough to warrant losing everything.
Known simply as "The Prison," Black Bolt uncovered its sinister machinations during his escape in 2017s Black Bolt (by Saladin Ahmed and Christian Ward). He learned of the Inhuman-built cosmic jailhouse using the Terrigen Codex, which holds the history of the Inhumans. Still, nothing prepared him for what was inside. He awoke bound and muzzled, not realizing it was one of the many times he'd been resurrected after deadly torture. He easily broke his chains and his cell door stood open. His muzzle proved more difficult to remove, but once free of it, he discovers he is still without his cataclysmic voice. The muzzle was just a ruse. The Prison played mind games, giving the inmate false hope for superpowers it's already stolen. Inside, everything was distorted by sentient rooms that act as a labyrinth, with shifting walls and warping floors.
The prison walls perceive an inmate's presence and torment accordingly. Black Bolt walked a gauntlet of chambers; some harbor skin-blistering heat, others, bone-freezing cold. He eventually uncovered a dark secret: this uncanny purgatory was redesigned by one of its own inmates (now dubbed The Jailer) who reaps inmates' superpowers. Spyder, the Jailer's henchman, uses a torture box to suffocate and/or maim inmates. Prisoners might survive Spyder, only to end up tortured to death by The Jailer himself. He then resurrects them to face their "penance in death" all over again.
The Jailer had two forms: one was a horrific warden who is terrifying in his own right and inflicted very real physical pain. The other was the former prisoner who split himself into pieces and could inflict debilitating psychological wounds. The Jailer's appendages and organs are held separately in tanks fitted with tubes that siphon the powers of The Prison's captives. This chilling arrangement worked like The Prison's engine room. As this "psychic vampire" fed on telepathic inmates, he was able to function as an omnipresent captor. He could distort reality, create constructs of himself, and elude detection. Because The Jailer had been feeding for centuries, he could control every side of prison life.
Despite this Black Bolt still managed to escape The Prison twice. First, with the help of his telepathic/teleporting dog Lockjaw, and again with help from something more powerful: the budding compassion felt between criminal and hero. Black Bolt's newfound fondness for The Absorbing Man and the telepathic child, Blinky, inspired him to beat impossible odds. The Absorbing Man's compassion for The Prison's child inmates motivated him to absorb Black Bolt's deadly voice. He used the power to kill The Jailer, and himself in the process. Meanwhile, the others were able to make their escape. Absorbing Man's moving actions led to a small, but epic funeral attended by old enemies Thor (Odinson) and Captain America. Thus, the ball-and-chain-wielding supervillain was redeemed in death.
Although Black Bolt survived he was forever changed. After his second jailbreak, he was stripped of his energy-manipulating voice, and his emotional core was crushed. Black Bolt was a character redefined by The Prison. He and his super-powered friends were forced to rely on something other than the Midnight King's formidable phonic power. The emotional bond, first between him and his canine familiar, and then among his fellow inmates was what made escaping The Prison possible. Stripped of their superpowers, the prisoners turned to old-school problem-solving, compromise, and cooperation.