Warning: SPOILERS through The Flash #49.
The latest chapter of the Flash War event sees both versions of The Flash - Barry Allen and Wally West - in a race that has them picking up speed as they circle the globe. Unfortunately, their actions cause a number of instabilities that threaten the Earth, forcing their allies in the Justice League and the Titans to take action against them.
Flash War spun out of the events of DC Universe Rebirth #1, which reintroduced the original Wally West (the first Kid Flash, who took up Barry Allen's mantle after his apparent death in Crisis On Infinite Earths) into the DC Comics Universe. Subsequent issues revealed that some unknown force was altering the universe, rewriting its history and altering peoples' memories as it pulled certain key figures, like Wally, outside of the new reality. Recently, Wally learned that his own memories had been altered and that he had been made to forget that he was the father of two super-speedster children, whom he was told were trapped in The Speed Force.
This led to Wally attempting to build up the power needed to break The Speed Force open and Barry, who had once tried something similarly drastic to stop his mother's murder in Flashpoint, running to stop his protege.
As Barry and Wally race, the tremors through The Speed Force begin to effect other aspects of the universe. We briefly see Swamp Thing and Zatanna discussing how both The Green and Earth's magical energy field are being disrupted. The race is even felt as far away as the planet of New Genesis, with the New God Highfather sensing something wrong within The Speed Force itself.
None of Earth's other heroes have any idea what is going on, beyond the fact that the two Flashes are responsible. In order to stop Amanda Waller from utilizing a lethal and permanent solution to the problem, the Justice League and Titans work to stop the deadly race. Unfortunately, The Flashes are moving so fast that not even Superman can catch up to them and Green Lantern's constructs can't slow them down.
This leads to an explosive finale which promises big things, which seem to further tie into recent events involving the various energy fields like The Speed Force that hold the DC Comics Universe together. How stable DC's world will be once the dust settles is a question every comic fan must now ask. One thing is for certain - the next issue of The Flash will be a game-changer!
The Flash #49 is now available from DC Comics.