User blog comment:Gracchus Mccarthe/If you don't yet know it, I'm obsessed with all things Zoom. I believe my first theory about him is correct. This post shows why./@comment-173.13.242.113-20160409143654

For me, there are too many plotholes for Jay and Zoom to be the same person. The big one is after Zoom kills Jay and brings him back to his lair, where he drops the body onto the ground and unmasks himself. Clearly it wasn't a speed mirage then. Furthermore, I don't see how Zoom could have possibly kept a mirage believable in between two worlds. From the 2x18 trailer, Zoom might lead them on into thinking he is Jay just to toy with their emotions, but they have to be separate people.

I support the twin theory. The way I think it will work out, on Earth 2 one twin was given to a foster family (most likely as Cobalt Blue was in the comics). He became Zoom, while his brother became the Flash. Furthermore, on Earth 1 I think Zoom, who found out his true origins and hunted his brother down out of anger and jealousy, kidnapped the other twin (the man in the iron mask!) so Jay nor his friends would find out that there are twins, thus keeping them from eventually finding out his identity.