The H-Dial is a powerful artifact capable of transforming the user for a limited time into a superhero. First found by Robby Reed, he used it to transform into a plethora of superheroes to defend his hometown from aliens, mutants, robots and a menagerie of odd disasters drawn to the dial. Long after two new H-Dials were found by two friends named Chris King and Vicki Grant. The friends used their H-Dials to combat a strange array of villains while being pursued by a relentless foe known as The Master, and aided by a mysterious ally, known as The Wizard. Eventually, it was revealed both the Master and the Wizard were alter-egos of Robby Reed, who had separated into them by using the Dial to disarm a dead man's switch and had never been able to recover the dial to return to his normal shape until then.
The superhero Hero Cruz wielded a form of the Dial inset in his belt; it was confirmed this version functioned by merging temporarily different versions of people through Hypertime.
Dialing it backwards (O-R-E-H) produces monstrous transformations ( Mindquake).
The H-Dial is mysterious in the sense that in spite of having been confirmed as been seen as far as 20,000 BC, it contains Interlac scripture, not invented until the time of the Legion of Super-heroes in the 30th century. This is due to time-traveling, but the origin of the Dial is still unresolved. Several have possessed its power, and most have come to regret it. For a limited time, it transforms the user into a superhero, one different each time, though at the end of an hour, the transformation must be reversed; if this is not undone, the hero's personality starts overtaking the host mind until the original is completely rewritten. A H-E-R-O series was issued, and at its end, the Dial was lost in space in 20,000 BC.
The alchemist Megistus desired the Dial to aid in his alchemical quest to shield humanity from the Final Crisis by mutating it, and Robby Reed managed to defeat Megistus envoy in New York by teaming up with the Metal Men and lending the Dial to Tin to transform into a more resilient hero to battle the monster.
Following the Flashpoint event, there are multiple H-Dials scattered across the world. The creator and origin is unknown, though they have been shown to have existed in ancient times (set up and weiled by a woman named Laodice). One of these H-Dials is found by Nelson Jent, who teams up with another weilder, Roxie Hodder (who goes by the name of Manteau). However, the H-Dials are not working properly, leaving the user with bizarre and impractical heroes. Manteau is trying to figure out what's wrong with the Dials, and brings Nelson on her quest. They are hunted by the 'shadow on the line', a mysterious figure who is hunting down H-Dial users (having killed Ex Nihilo while she possessed a dial). Another Dial has been confirmed as being used by a hero in Canada.
Functionality of the H-Dial
This incarnation of the H-Dial takes the powers of heroes from alternate universes, leaving them powerless as long as they are in use. The wielders are left with false memories, and eventually can no longer differentiate themselves from the heroes they have dialed.
Recently, Roxie and Nelson have obtained a Dial from the Canadian military that they believed to be another H Dial. However, it would not dial up a hero and while interrogating its user, who was in a coma-like state, they discovered that the sequence 7-4-3-3 was used to activate, spelling out S-I-D-E, as in 'sidekick.' The sidekick is instinctively subservient to the hero, explaining why Mason Jones listened to Nelson during their encounters.