The Flash recap: Season 7, Episode 2, "The Speed Of Thought"
2 The hour opens with a tribute to the lost Wellses, at which Cisco is mysteriously now present. This only makes the end of last week’s episode feel like more of a missed opportunity, as there doesn’t appear to be any good reason Cisco wasn’t present at Nash’s death...but as we’ll soon learn, the Wells mourning is a bit premature anyway. In any event, Cisco has been working on a portal to the Mirrorverse, but has run into technical problems. In the ensuing spew of techno-babble, it becomes clear that Barry’s thoughts are now traveling at super-speed. He’s figured out the problem...
Source: avclub.com