The Flash: One-Minute War Special explains new speed force villains known as the Fraction

gamesradar.com:

Last month DC announced that The Flash will enter a twice-monthly schedule starting in January, with a new 'One-Minute War' arc that kicks off in issue #790. And following that, the publisher will release part two of the arc in The Flash #791, followed by The Flash: One-Minute War Special #1, a double-sized one-shot Newsarama readers get to hear about first.

In 'One-Minute War,' the Flash faces off against an armada of aliens known as the Fraction who are also connected to the Speed Force. This means the Flash Family's usual advantage - moving so fast their enemies are almost in slow motion - is nullified because the Fraction moves just as fast. 

The story arc will also feature the return of Barry Allen to Earth-0/Prime and the pages of The Flash following a two-year absence while he was caught up in the events of Infinite Frontier and Dark Crisis on Infinite Earths.

The aptly-named 'One-Minute War' literally takes place in 60 seconds of real-time, but that can last an age for a speedster. Writer Jeremy Adams told CBR (opens in new tab) who announced the story arc, "[The Fraction] also have learned to utilize the speed force mechanically. So, they have ships, vehicles, etc. moving at super-fast speeds so they can land and take over without any resistance. And because they are moving so fast, other superheroes can't help. This is an event that solely relies on the speedsters of Earth."

In The Flash #791, written by Jeremy Adams, penciled by Roger Cruz, and inked by Matt Banning, the heroes are split as the Fraction continues its invasion. While the Flash Family make a plan and try to fight off multiple attacks, they're faced with yet another threat.

The villainous Miss Murder is hunting the Flash Family too, and she has