Mister Miracle (Scott Free), Big Barda, and their manager Oberon are rehearsing one of Scott's escape attempts. When the smoke clears, Oberon is gone and Granny Goodness reveals that she kidnapped him to force Mister Miracle to rescue Kalibak from Vermin Vundabar. Kalibak is being held in the X Pit on Apokolips as part of Vundabar's plan to take control of the planet in Darkseid's absence. Granny wants Kalibak for the same reason and threatens to kill Oberon if Miracle doesn't help her.
Miracle and Barda go to the Justice League, but J'onn turns down their request. The Flash, bored with being treated as an immature hero, secretly goes to them and offers his help. The three of them travel to Apokolips and after defeating a squad of soldiers, enter the X Pit building. Scott grew up there when he was trained/tortured by Granny Goodness, but Vundabar has changed the layout.
Flash quickly finds the imprisoned Kalibak and they prepare to leave. They are separated and Miracle is trapped in a flooding chamber while the others are dumped into a pit. Miracle manages to escape and rescue them, and they then fight their way past more soldiers. Vundabar destroys the entire complex but they escape once more and turn Kalibak over to Granny. It's actually a ruse - J'onn has shapeshifted into the form of Kalibak and scans Granny's mind to obtain Oberon's location. The Flash rescues the manager in the nick of time and they all escape with Kalibak imprisoned on Earth and both sides still at war with each other, unable to use Darkseid's son as a pawn.
Mister Miracle first appeared in Mister Miracle Vol. 1 #1 (March-April 1971). Created by Jack Kirby as part of his Fourth World setting, Scott Free was the son of Highfather, the ruler of New Genesis. As part of a pact between New Genesis and Apokolips, Highfather and Darkseid sent each other their sons. Scott Free was raised by Granny Goodness to become a killer but met Metron and the scientist Himon, and learned enough to escape the planet and flee to Earth. There he met Thaddeus Brown, an escape artist calling himself "Mister Miracle." Scott learned everything Brown knew and when Brown was killed, put his experience to use both to take Brown's place and avenge his murder.
Scott Free became involved in the affairs of Apokolips and it was there he met his wife-to-be, Big Barda. She was a member of Darkseid's Elite Female Furies sent to Earth to recover Free, but they fell in love and were later married. Mister Miracle has since been a member of various incarnations of the Justice League and maintains a home in suburban America. He possesses superior physique due to his heritage as a New God, wields New Genesis technology such as flight discs, an omni-cube, & a Mother Box, and is a competent hand-to-hand fighter, but his primary ability as a superhero is the training that lets him bypass any lock, barrier, restraint, or security device. This is his first significant appearance in the WB animated universe.
Big Barda first appeared in Mister Miracle Vol. 1 #4 (Sept. 1971). Created by Jack Kirby as part of his Fourth World series, Barda was born on Apokolips and trained as a shocktrooper. She was modeled on Jack Kirby's wife Roz and actress Lainie Kazan. Her prowess was such that she rose through the ranks and became a member of the Female Fury Battalion. She met Scott Free on Apokolips during a raid and was attracted to his free spirit. Later, when the Furies were sent to Earth to recover Free, she defected and remained with him on Earth. They were later married, and Barda has served with the Justice League on occasion. She has super-human strength and resilience, wears battle-armor, and wields the "Mega-Rod," fires energy blasts, opens teleportational "boom tubes," and allows her to fly.
In the WB animated universe, Barda first appeared 40 years in the future in Batman Beyond in the episode "The Call (1)". There it was revealed she was a member of the future Justice League and had abandoned her battle armor (or never bothers to don it), although she still wields the Mega-Rod. Little was revealed of her background other then that she was related to Mister Miracle in some manner. This is her first appearance in Justice League Unlimited.
Vermin Vundabar is another creation of Jack Kirby for his Fourth World setting, and first appeared in Mister Miracle Vol. 1 #5 (Nov-Dec 1971). Vundabar, like several New Gods, has studied one particular aspect of Earth history and emulates it. In his case - Prussia in the late 19th and early 20th century. He is a sadistic toady of Darkseid's who tends to follow anyone in power. Like the other New Gods, he possesses inherent strength and endurance but seems to have no other powers and typically relies on the arsenals and armies of Apokolips when there is some duty to be carried out, and typically leads from the rear rather then face his enemies directly. This is his first appearance in the WB animated universe.
Granny Goodness first appeared in Mister Miracle Vol. 1 #2 (May-June 1971). Created by Jack Kirby as part of his "Fourth World," she is the head of Darkseid's Orphanage and trains Apokolips' children to become unquestioning soldiers for her lord and master. As a New God she possesses considerable strength and endurance, wields a series of high-tech weapons, and has access to Apokolips' military might. She also has a keen insight into the human psyche and is capable of breaking almost any individual through mental and physical hardship. She has served Darkseid more-or-less loyally through the years but has been punished for even the slightest indication of failure.
In the WB animated universe, Granny Goodness appeared briefly in flashback in in Superman: The Animated Series in the episode "Apokolips...Now!", but made her first full appearance in "Little Girl Lost", Much of her background was unrevealed but her abilities and position in Darkseid's hierarchy appear the same as above. She appeared sporadically in that series and this is her first appearance in Justice League Unlimited.
Oberon first appeared in in Mister Miracle Vol. 1 #1 (March-April 1971) and is another Jack Kirby creation. When Scott Free came to Earth and trained with the original Mister Miracle, Thaddeus Brown, Oberon was Brown's sidekick, manager, and confidant. When Scott became the new Mister Miracle, Oberon remained with him and has stayed with him ever since. Little has been mentioned of his background - due to his diminuitive size he and Brown may have met in the circus. Oberon possesses no superhuman abilities but is a skilled manager (with the occasional lapse) and has unswerving loyalty. He is a support staffer for the Justice League, and during his time with the League often stood monitor watch. This is his first appearance in the WB animated universe.
James Steranko, born 1/5/1938, spent his early years working as a magician and escape artist, but later became a freelance newspaper artist. After working at Harvey Comics, he was hired as a penciller for "Nick Fury, Agent of S.H.I.E.L.D." Steranko brought his unique sensibilities to the strip with Benday dots, moire screens, and other artistic varieties. He worked only briefly for Marvel then went independent and has since worked on book covers, movie illustrations, and maintains his own publishing venture, "Supergraphics." Jack Kirby largely based Mister Miracle the escape artist on Jim Steranko.