Synopsis: In a kind of sequel to the earlier Flash (I) and Flash (II) team-ups in The Flash, vol. 1, various criminals-- including "Flash of Two Worlds" star, The Fiddler--capture both Flashes so that they alone can control travel between the two Earths.
By exchanging places with each other, each Earth's Crime Champions hope to gain the tactical advantage of surprise over their opposite number's super group. They appear to be on the verge of succeeding.
Unfortunately for them, the JLA and JSA learn of each other's existence, and they begin to hatch a plan to pull the same sort of switcheroo on their respective Crime Champions. Key to the success of this mission is the final rescue of the two Flashes. With the outcome still very much in doubt, both Green Lanterns head off for the "transition zone" between the two Earths to free the Flashes.
Synopsis: Having switched places last issue, the JLA and JSA begin this issue on the wrong Earth, but fighting the right Crime Champions. Breaking up into a several groups, the JLA and JSA take out "their" Crime Champion with relative ease.
All appears to be going well, until the Green Lanterns progress with their plan to free the captive Flashes. When they attempt to do so, however, they encounter effective resistance from Faust and The Wizard. These villains' magic works to ensnare every single hero on both Earths into a special cage specially built for each hero. These cages stop the heroes from using their powers. And they're very effective.
Unfortunately, neither Faust nor the Wizard planned on the Green Lanterns using their rings to mimic Ray Palmer's Atomic power. The two "think small", and slip out of the cages. It is then a relatively simple matter for them to free all the heroes. It's then easy for the combined force of the JLA and JSA to defeat both Crime Champions head-on.
Synopsis: On a parallel world, Johnny Quick, Power Ring, Superwoman, Owlman and Ultraman--together known as the Crime Syndicate of America--have discovered a way to get to a world very much like their own...but different.
On this "new" Earth, they discover that their alternate selves--Flash, Green Lantern, Wonder Woman, Batman and Superman--are fighting for the "good" in others. Sensing weakness, they invade what these do-gooders arrogantly call "Earth 1". Unfortunately, they discover that their "good" counterparts are good fighters. The Crime Syndicate is very nearly destroyed. At the last moment, though, they utter a "safe" word that returns them instantly to their Earth.
Still thirsting for victory, the Crime Syndicate learns of yet another Earth, and they set out to tackle the Justice Society of America. Unbeknownst to them, however, the JLA manages to contact the JSA on Earth 2, and the two supergroups thus work together again to eliminate the "surprise" of an extra-dimensional threat.