Spoilers follow for tonight's season finale of The Flash.
As Flash was accessing the speed force and travelling through the wormhole he saw glimpses of his past, present - and future!
Now we know why Danielle Panabaker dropped spoiler bombs the other day - it's because this episode gave us a first look at Danielle Panabaker as Killer Frost! Check it out below.
The episode also saw Wells reveal to Cisco that Cisco is a metahuman, which explains why Cisco could remember the alternate timeline. In DC Comics lore, Cisco goes by the name of Vibe, and was recently given a new set of powers possibly making Cisco one of the most powerful metahumans on the planet, which we now see seems to fit in with The Flash TV series.