Part of the fun of the 21st century superhero shows is the effort put into worldbuilding. Not just the cast of characters but the entire ecosystem of the city, the attitudes towards heroes and villains from the civilians, and histories that hold sway over
The fun of the CW superhero shows—Arrow, The Flash, DC’s Legends of Tomorrow, and (as of season two) Supergirl—is the way they’ve worked them into the same universe (or at least connected universes, in the case of Supergirl). You could say the same of the Marvel shows on Netflix, which exist in a tight, decidedly earthbound and mortal world confined almost entirely to New York City. They have a focus, more like a series of graphic novels in a shared universe, and their all-at-once release pattern emphasizes that unity. The CW shows, for better or worse, are more like monthly comic books, with stand-alone episodes like individual issues as well as ongoing story arcs and crossovers with sister series. They are looser, with more digressions, which can also mean more opportunities to play with the possibilities. And because they all roll out concurrently, they offer a possibility right out of the comic book world: stories crossing over from one series to another. This season offered a story that brought all four shows together.
The 2016-2107 seasons of all four shows are now available on DVD and Blu-ray (they were staggered over the past couple of weeks). One note that is applicable to all four shows: these set do not feature the episodes from the sister shows of the crossover stories so you’ll need all four sets to see the full story (though to be fair the Supergirl episodes offer little more than a few minutes of set-up for their portions of the stories). What each set does include is a featurette on the big crossover event (each one focused on the show’s POV).
The Flash: The Complete Third Season(Warner) of the most family friendly of the prime-time superhero show on TV opens with Barry Allen / The Flash (Grant Gustin) facing repercussions from his decision to save his mother’s life by changing history and his attempts to repair the results in a world bearing the scars of his actions. his girlfriend Iris (Candice Patton) is no longer speaking to her father Joe (Jesse L. Martin), Cisco (Carlos Valdes) holds a grudge against him, he’s working with a senior forensics scientist, Julian (Tom Felton, of the Harry Potter movies), who dislikes him, and he’s hunted by a new villain named Savitar. Meanwhile, Joe’s son Wally (Keiynan Lonsdale) develops speed powers and is mentored by Barry to become Kid Flash, and Caitlin (Danielle Panabaker) struggles against the villainous Killer Frost taking over her identity. You know, comic book melodrama.