"New Frontiers": Donna Troy, Bob the Monitor, Green Lantern and Jason Todd (colloquially known as the Challengers) arrive on Earth-3 – a world dominated by a team of super-villains known as the Crime Society. Immediately, a fight breaks out, and the Challenger
- Next time, let the cute girl talk to the children.
- — Una
Synopsis for "New Frontiers"
Donna Troy, Bob the Monitor, Green Lantern and Jason Todd (colloquially known as the Challengers) arrive on Earth-3 – a world dominated by a team of super-villains known as the Crime Society. Immediately, a fight breaks out, and the Challengers and the Crime Society begin tearing up the streets of Metropolis. From out of nowhere, a purple-haired clown with a giant hammer springs into action and begins assisting the heroes. He joyously refers to himself as the Jokester.
Back on New Earth, Holly Robinson prepares for her journey to Paradise Island. She writes a letter to Selina Kyle and leaves it at the front desk of the shelter. Someone (presumably Athena) takes the letter and tears it up.
In the Fifth Dimension world of Zrrf, Mister Mxyzptlk walks down the street walking his pet goldfish Superman while conversing with his companion Miss Gsptlsnz. Suddenly a dimensional aperture appears and Mxyzptlk is spirited away.
In Turkey, Eclipso continues to corrupt Mary Marvel. A group of soldiers approaches them in a threatening manner, demanding them to leave this protected landmark. Mary Marvel turns the soldiers into stone, and Eclipso casually finishes them off by flicking their heads off with her finger. Mary expresses no remorse over this callous deed, and says that she actually feels pretty good about herself.
Meanwhile in "The 'Burbs", Karate Kid and Una arrive at the home of Buddy Blank and his grandson. Buddy greets the strangely dressed visitors with a baseball bat, until the Karate Kid tells him that he needs to find Brother Eye.
At Project Cadmus, Serling Roquette puts Jimmy through another battery of tests. The process causes Jimmy's body to mutate into a hideously monstrous form.
Back on Earth-3, the Challengers continue to fight the Crime Society, until Bob the Monitor confirms that Ray Palmer is nowhere to be found in this reality. With that said, he opens a rift, and the heroes leave for another dimension. The Jokester decides to join them and becomes a member of their party.
Moments later, Monarch and Forerunner arrive on Earth-3. Monarch offers the Crime Society the opportunity to become conquerors of the Multiverse.
In the Multiversal Nexus, the Monitors continue to debate over what to do about Bob. One of the more aggressive Monitors deems his brother a traitor and declares that he must be stopped at all costs.
Appearing in "New Frontiers"
- Holly Robinson
- Jimmy Olsen
- Karate Kid
- Mary Marvel
- Challengers from Beyond
- Eclipso (Jean Loring)
- Crime Society
- Athena (Cameo)
- Forerunner (Cameo)
- Kamandi (Cameo)
- Miss Gsptlsnz
- Mister Mxyzptlk
- Selina Kyle (Behind the scenes)
- Fifth Dimension
- New Earth
Synopsis for "The Origin of the Joker"
The Joker was once a failed comedian who was manipulated into a life of crime. He adopted the costumed identity of the Red Hood and ran afoul of the Batman. During their initial confrontation at a chemical processing plant, the Red Hood fell into a vat of chemicals which turned his skin white, and his hair green. It also drove him insane. Since then, he has adopted the identity of the Joker and has become Batman's arch-nemesis.
Appearing in "The Origin of the Joker"
- Batman (Cameo)
- This issue shipped on September 26th, 2007.
- 1st full appearance of Earth-3. The Crime Society of Earth-3 first appeared in a cameo in 52 Week Fifty-Two. They also made a cameo appearance in Countdown #32. They chronologically appeared last in Countdown: The Search for Ray Palmer - Crime Society #1.
- Mister Mxyzptlk as he appears in this issue, physically resembles his Earth-Two counterpart Mister Mxyztplk (note the spelling).
- "The Origin of the Joker" is told from the perspective of the Joker himself, and may or may not contain factual information. Flashbacks from the Joker's origin are synonymous with the history and imagery provided in Batman: The Killing Joke.
- In "The Origin of the Joker", one of the Joker's perceived possible origins is that of a mob killer named Napier. This is a nod towards the characterization of the Joker in the 1989 film Batman. In the movie, Jack Nicholson plays a mobster named Jack Napier who later becomes the Joker. The Jack Napier alias has never been established as a canonical real name for the comic book version of the character. To date, the Joker's true name is still a mystery.
- 1st New Earth appearances of Buddy Blank and Kamandi. In Pre-Crisis continuity, both characters hailed from the reality known as Earth-AD. Buddy was the grandfather of Kamandi and eventually became the first O.M.A.C.. In this issue, Buddy's grandson is seen playing with a brown dog. This may be the New Earth counterpart to Doctor Canus, a talking canine character who appeared regularly in the Kamandi comic book series.
- Countdown: Arena
- Countdown: The Search for Ray Palmer
- Countdown to Adventure
- Countdown to Mystery