Barry and Oliver wake up living one another's lives but no one else remembers reality any different. Meanwhile, a meta-hunting robot is unleashed on the city.
The Flash episode “Elseworlds, Part 1” was filmed in Vancouver, Surrey, & Langley in Canada.
Dr. John Deegan has all of his students leave after promoting eugenics during a class and when he is going to his car afterwards he is confronted by the Monitor who presents him with his book.
Oliver tries to adapt to his new speed powers while stopping a robbery and accidentally zaps a dangerous robot with his lightning.
Barry tries to get a hang of the whole Green Arrow schtick while stopping a gang battle with Diggle.
Oliver zips Barry and Diggle to an empty warehouse to discuss their shared predicament.
Kara is spending time in the country with Clark Kent and Lois Lane when Oliver and Barry pop in from Earth-1 to ask for her help.
Barry, Oliver, Kara, and Clark team up to try to take down Amazo but only manage to make it more powerful when it acquires their powers.