Team Flash is weary of all the evil metahumans coming from Central City Earth-2, and is making a plan to put an end to Zoom's master plan of killing Barry Allen and being the only speedster in the multiverse.
Throughout Season 2, metahumans have been attacking Barry at Zoom's command, and it has allowed us to understand that for every person in Barry's earth, there is a doppelganger in Earth-2. In episode 5 Barry and Dr. Light, a lookalike of his girlfriend Linda Park, fought against each other, and flash defeated her. At the end of the episode, Barry realizes there is no point in delaying the inevitable facing Zoom. He seeks help of everyone, from Dr. Wells of Earth-2, Jay Garrick Flash of Earth-2, in defeating Zoom, but Jay, who has tried to defeat Zoom multiple times in his world, refuses to watch get Barry killed.
In episode 6, we see the team training Linda of Earth-1 to pretend to be Dr. Light and pretend to fight Flash, before he gets hit and falls down. The team hopes that Zoom will see the fight, and will come through the portal to collect Flash's body, and when he does, they can defeat him. From what Jay has said, it is not going to be that easy, granted that even Jay Garrick himself has admitted he was never as fast as Barry
Can Eddie Thawne be Zoom? Theory for Eddie Thawne
One of the most popular theories is Zoom of Earth-2 will be Eddie Thawne who sacrificed himself to save Central City in the Season 1 finale. Ever since his death, fans have speculated his return, but we had all assumed it would be as another villian: Cobalt Blue. I'm also thinking that Eddie caused the singularity to reappear. If you guys remember, it was Eddie's intervention from shooting himself that caused the singularity to reopen after it had been closed, so i guess you could argue that Eddie's sacrifice caused the singularity to become connected to only his timeline in attempt to fix everything. The singularity was also made from the speed force. When Barry created the singularity using speed force, there was maybe some residual energy left when it reopened so which Eddie's body git sucked in, it could have absorbed that energy, healed him and had taken him to Earth-2 to start formulating some kind of revenge plot.
Can Henry Allen be Zoom? Theory for Henry Allen.
Another group of theorists suggest Zoom would be Henry Allen who recently got out of prison, but left Central City abruptly because he thought his presence would distract Barry from his responsibilities as The Flash, but think about it, ehy would Barry's father, who has been in jail for almost 15 years not be with his only son and cherish this time with him? I'm guessing he left because he needed to be Zoom. The Henry Allen I'm referring to is Henry Allen Earth-2. I'm not sure what could have happened to Henry Allen Earth-1, but i think Henry Allen Earth-2 might have taken Henry Allen Earth-1 to Earth-2. At least that's my theory. There is a coincidence in episode 6 and 7 when The Flash is fighting Zoom. Zoom is carrying Linda Park Earth-1 and is about to throw her off the rooftop of S.T.A.R Labs and he says "I've been fishing." That leads us to episode 7. Henry Allen is back, and him and his son are having a talk and Henry Allen says "I was trying to call but you can't get a cell in Granite Peak Park." Barry says " What, you went camping by yourself?" Henry Allen says " Yeah, Yeah i got a tent, i went fishing everyday." So as you can see, Henry Allen says he went fishing and so did Zoom. See the coincidence. I wanted to point out one more thing. Look at the picture below.
Take a very close and good look at the eye structure.
Who do you guys think is Zoom, Is it Eddie Thawne, or is it, Henry Allen?