That ' s all Black Friday shit . This is completely different <| sep |> Thank you , holy shit . <| sep |> Sure , it makes sense . Crossovers into the flash series with the arrow crew still made sense to watch . You ' d get a sense of ' ok so barry seems to like this particular girl but there ' s something more going on ', but that ' s fine . In the end the shows are good entertainment , but not the sort of intricate artistic masterpieces where you need the whole picture to understand anything . Superheroes good , aliens bad , gg . Unless there ' s a precursor to the invading aliens on any of the series that leads up to this . Because to me coming from just Arrow , it comes right out of the blue that there ' s suddenly a massive invasion of aliens p If there ' s a leadup to it , I ' d probably want to watch it first just to get the whole story , even if it ' s not essential viewing .