This is a work in progress but clearly we need someplace to discuss the practical applications of metahuman powers. Edit: I've got the old OP over but need to update it a bit as it's like two seasons out of date.
I'm going to state what I feel the thread has been doing: Spoilers for the current episode, especially for major plot points. Beyond that....eh, use your judgement. If it's not from the current season nobody has shown any evidence of caring. If you're dealing with anything unaired/casting news/future stuff then absolutely put that in spoilers and label them.
The Flash is a DC Comics superhero who debuted in Showcase #4 in 1956, created by writer Robert Kanigher and artist Carmine Infantino. Central City police scientist Barry Allen is working late hours in the crime lab one rainy night when a bolt of lightning strikes him through the open skylight, sending him flying into a rack of unlabeled chemicals. The combination of lightning and chemicals ends up granting Barry the power to travel at superhuman speeds, and he dons a red costume to fight crime in his new identity as the Flash, the fastest man alive. Though his superhero name and powers of super-speed were based on an older character from 1940, everything else, from his secret identity to his costume to his origin story, was changed for the 1956 reboot, which is generally credited with revitalizing the popularity of superheroes and kicking off the Silver Age of comics (1956-1972).
He became one of the original members of the Justice League of America in that group's first appearance in 1960, alongside Superman, Batman, Wonder Woman, Green Lantern, Aquaman, and the Martian Manhunter. Since then, the Flash has appeared regularly in Justice League-based media:
In 1990, Flash got his own show, starring John Wesley Shipp as Barry Allen/The Flash. It was heavily influenced by the style and tone of the Tim Burton Batman that had been such a runaway success the year before, with a very set-designed, urban gothic fairytale feel (on a TV budget). A good word for it, looking back, is "quirky." Shipp gave a terrific performance, though.
The show also marked the first of Mark Hamill's appareances as the Trickster over what would come to be three separate fictional universes and 25 years.
That brings us to the present. In season two of CW's Arrow, Central City police scientist Barry Allen, who has a personal interest in weird and inexplicable crimes, traveled to Starling City to help Oliver Queen/Arrow solve a seemingly impossible case. At the end of the two-part episode, Barry returns to his job in Central City, only to be struck by lightning caused by the explosion of the city's new high-energy particle accelerator.
The first episode of CW's The Flash picks up where the Arrow two-parter left off. Barry awakes from a nine-month coma and soon learns that his body and perception of time have changed in inexplicable ways, granting him the ability to travel at supersonic speeds. He resolves to use this power to fight crime, but his motivation is more than simple civic duty: as a ten-year-old child, he witnessed his mother's murder at the hands of a man inside a ball of yellow lightning, before suddenly finding himself whisked away at impossible speeds to safety many blocks away. The police didn't believe his story, and Barry's father has spent over a decade in prison for the crime.
And Barry isn't the only one who was given powers the night the particle accelerator went haywire. These metahumans are everywhere, and some of them are nasty. Barry has to team up with his new friends at STAR Labs to help contain the metahuman menace while working overtime to catch the man who murdered his mother and prove his father's innocence.
Barry Allen/The Flash (Grant Gustin) - A forensic scientist working for the Central City Police Department. After his father went to prison for his mother's death, Barry went to live with Joe West, the detective who closed the case, who became almost a surrogate father to him, as well as a mentor at his job. Barry is smart, passionate, and has a strong sense of justice, but can let his impulses and emotions get away from him, a quality some of his enemies are learning to exploit. Barry has nursed a crush on Iris since childhood but has only recently ever spoken of it.
Joe West (Jesse L. Martin) - The man who put Barry's father in prison but felt responsible for the boy's welfare. Avuncular and sharply observant, Joe is a good man and a good cop but has a bad habit of withholding information from people "for their own good." This has recently blown up in his face.
Iris West (Candice Patton) - Joe West's daughter, now a junior reporter at Central City Picture News. She believed the rumors of "the Streak" before the police or media and tirelessly dug for the truth, but was kept in the dark about Barry's secret identity, and his feelings for her, until recently, leading her to feel hurt and betrayed. She feels something for Barry, too, but is in a relationship with Det. Eddie Thawne, Joe's partner in the force.
Cisco Ramon (Carlos Valdes) - STAR Labs' mechanical genius, Cisco is responsible for creating the Flash suit and crafting the high-tech gadgets that Barry sometimes needs to help catch supervillains. An enthusiastic consumer of comics and movies, Cisco has also given himself the unofficial responsibility for coming up with the codenames for all of the Flash's metahuman archenemies. He shares a name with DC's vibration-powered disco-themed hero Vibe and might be getting his own powers at some point.
Caitlin Snow (Danielle Panabaker) - STAR Labs' resident biologist and medical expert, Caitlin is responsible for monitoring Barry's vital signs through the Flash suit and crafting antivenoms, growing clones in petri dishes, and all that messy organic stuff. The apparent death of her fiancee Ronnie Raymond in the collider explosion exacerbated her natural tendency to be pensive and withdrawn, but Barry and Cisco's enthusiasm - as well as the discovery that Ronnie is alive, mostly - has revitalized her. Caitlin shares a name with DC's ice-powered villainess Killer Frost so might be taking a dark turn in the future.
Eddie Thawne (Rick Cosnett) - Joe West's partner on the police force and Iris's would-be fiancee before being abducted by the Reverse-Flash, Eddie is a smart, dedicated, loyal, and ethical cop who is a good boyfriend to Iris and a good friend to Barry - somewhat to Barry's chagrin, since Barry's torch for Iris would be easier to carry if Eddie were a jerk.
Dr. Henry Allen (John Wesley Shipp) - Barry's father, who has languished in prison for a decade and has deduced his son's secret identity - but refuses to let Barry break him out, insisting that his name be cleared "the right way."
Captain Cold (Wentworth Miller) - Leonard Snart is a precise, calculating career bank robber who's in his line of work for the thrill and for the mental challenge of pitting his planning and expertise against the police and, now, the Flash. Having stolen some experimental weapons from STAR Labs to even the odds - in his case a freeze gun - he leads a team of thieves called The Rogues, and has learned the Flash's secret identity, but made a pact with Barry not to reveal it, and to avoid harming civilians, if the Flash will let Cold continue to play his game.
Dr. Harrison Wells - The brilliant physicist behind STAR Labs and creator of the particle accelerator that gave Barry his powers (as well as seemingly cost Wells the use of his legs), Dr. Wells has been Barry's mentor and guide, helping him learn to come to grips with his powers and pushing him to excel. An enigmatic man, we've known from the beginning that Wells can secretly walk and that he has a newspaper in the basement with a date of 2024 and a headline about the disappearance of The Flash. And now, at last, we've learned the truth: the real Dr. Wells was murdered 15 years ago, his place in time taken by Eobard Thawne, a time-traveling supervillain from the 25th century, better known as the Reverse-Flash: the "man in yellow" who killed Barry's mother.