Gee, what a coincidence that Joe's biological son just happens to have a fascination with speed... (Plus the coincidence that the guy Iris was investigating just happened to be the final victim of the metahuman Barry was investigating.)
And that's got to be one of the most contrived and convoluted ways to murder someone ever devised -- turn the tar of the roadway into a semicircular ramp in order to cause a drag racer's speeding car to reverse direction and become a projectile aimed at the target. What was Tar Pit's civilian name again? Rube Goldberg?
Perhaps the most interesting part was the depiction of Barry's speed-learning ability. So he can pick up temporary expertise by thorough speed-reading, but it only lasts in short-term memory for about half an hour? Interesting. I'd like to see other applications of that. Barry doesn't get to be a scientist often enough. (And it's something that could only really be done with print books. It'd be useless with videos, which don't play sound in fast-forward, and I'm not sure a computer screen or e-reader could refresh fast enough.)
I liked Barry's speech, not only about forgiving Wells, but about recognizing that they couldn't just ignore the danger Zoom posed to Earth-2. That was a nicely superheroic sentiment. And of course it'll be fun to see the team visit Earth-2 next week.
Although as Wells keeps stressing, it's his Earth-1. Maybe they should call them Earth-1 and Earth-A...