This is every episode of The Flash (22 total) in the order they appear on the TVD set.
1) Pilot
A biker gang is terrorizing Central City. Barry fights crime in the lab while brother Jay fights on the street. Barry is under appreciated and desperate to prove himself by stopping the gang. An accident speeds up his body impossibly fast which becomes the weapon he needs to fight the gang and avenge his bother’s murder.
2) Out of Control
Homeless people are vanishing and those remaining are getting scared. Barry is determined to help them even though he has to defy the police force to do it. Meanwhile he goes head to head with a scientist friend of Tina’s over science versus morality. Does he have a point or is he just jealous of Tina’s relationship?
3) Watching the Detectives
Someone is torching buildings while an investigator is chasing the ID of the Flash. Trying to stop the bad guys while protecting his secret becomes more complicated when Barry starts falling for the PI, but it really hits the fan when a dirty DA uses knowledge of Barry’s true identity to turn him into a puppet.
-This is the introduction of Megan Lockhart.
4) Honor Among Thieves
Criminal masterminds are after a priceless artifact. Barry sets out to protect the museum but thin police resources and a personal history with the curator are causing tension.
5) Double Vision
Flash has fallen under the control of a mad scientist. As people are plagued by a “demon” Barry notices strange things happening in his life.
6) Sins of the Father
A criminal escapes from a chain gang, and he wants Barry’s father’s blood for putting him away. This crook has tricks up his sleeve that challenge even the Flash.
7) Child’s Play
Criminals blow up their incriminating evidence but not before a young pickpocket unknowingly swipes some of it. While the cops race to stop the influx of a new, dangerous drug on the street Barry plays babysitter to a juvenile delinquent.
8) Shroud of Death
Someone is killing off city officials in nasty ways. Barry races to put the pieces together before his boss becomes the next victim. Meanwhile Julio is getting suspicious of Barry, and Tina considers taking a job offer that will require her to move away.
9) Ghost in the Machine
The Flash wasn’t Central City’s first super hero. Nightshade stopped the Ghost once, but now the villain is back and ready for mayhem. Nightshade comes out of retirement to fight the menace once again and teams up with the scarlet speedster.
10) Sight Unseen
An invisible criminal is terrorizing Star Labs. He’s released a toxin that gives Tina less than 4 hours to live. The FBI won’t allow investigation of the case and arrests Barry for working on an antidote.
11) Beat the Clock
A jazz musician is about to be executed for killing his wife. As a close friend, Julio is torn up about it and convinced of his friend’s innocence. He may be right but cop pride from the investigators and his own emotions get in the way of hunting new evidence. Can even the Flash solve the case in time to save Julio’s friend?
-This one is more story-driven than most of the others and has less reliance on super heroics. It’s also one of the best episodes from a dramatic standpoint.
12) The Trickster
Megan is back and about to be sawed in half by the madman James Jesse. Saved and reunited with Barry there’s a romantic spark, and boy is Tina jealous. Problem is James is in love with Megan, too, and is convinced the Flash has kidnapped and brainwashed his true love. James becomes the Flash’s most dangerous foe, Trickster.
-Mark Hamill plays this role with terrific insanity.
13) Tina Is That You
Barry has nightmares about Tina turning against him. It’s part of a side effect of his fast metabolism that won’t let him sleep well. In a scientific attempt to help his nightmares are transferred to Tina’s mind. She becomes the next villain Flash has to stop.
-This is a surprisingly bad episode. It feels corny instead of dramatic probably more so than any other episode.
14) Be My Baby
Barry meets a scared, lost girl being chased by some tough customers. They want her baby girl. Barry helps them find shelter, but that’s not the end of it. The girl’s father is a criminal mastermind that will stop at nothing to reclaim his heiress.
15) Fast Forward
Pike is a free man based on a legal technicality, and his lawyer is asserting that it was actually the Flash that killed Jay Allen. On top of that she’s managed to get Barry suspended from the police force. So he decides to take some time off to regroup. Before he leaves town Pike hits him with a missile that knocks him into next year; actually 10 years. In the future the Flash’s absence has allowed Pike to take complete control, and those that knew Barry think that he abandoned them. Trapped in a crummy future without his powers, with Pike after his head, and with Tina hating his guts he’s pretty much done for.
16) The Deadly Nightshade
There’s a vigilante out there who’s ready and willing to use deadly force, and he’s going by the name of Nightshade. Flash teams up with the original Nightshade, Desmond Powell, to stop the killer. Meanwhile a pop psychologist calls into question the Flash’s sanity.
17) Captain Cold
Captain Cold is freezing people to death and even the Flash is vulnerable. He has to face this menace as well as deal with a pain-in-the-butt reporter that keeps getting in the way.
-Finally a classic comic book villain played chillingly well by Michael Champion.
18) Twin Streaks
Underground scientists are trying to create super fast Flash clones but can’t get one that can survive under the high speeds. Using Barry’s tissue they finally create Pollux. He’s a child in a super man’s body, not evil but without identity or a moral compass. Tina is already afraid that Barry is burning himself out so how is he going to stop someone with his powers at their peak?
-While Pollux is not a classic Flash villain he is something of an amalgamation of Reverse Flash, Speed Demon, and Cobalt Blue.
19) Done With Mirrors
Tina’s mother comes into town for a visit causing a great deal of tension but not as much as the criminal that locks lips with Barry in front of them. Stasia double-crossed her partner in crime who uses sophisticated imaging technology to confuse and manipulate people. With bad guys after her she turns to Barry for unwitting help, but as manipulative as she is she is no match for Mirror Master.
-Check this out, another classic villain! David Cassidy plays Mirror Master.
20) Goodnight Central City
Someone has created a device that puts people to sleep and has plans to knock out the entire city for a crime spree. Internal Affairs thinks Barry is dirty based on circumstantial evidence and a computer error generated debt to his name. When Tina finds out the sleep machine will kill the whole city if it’s left on too long the only hope for salvation is left locked behind bars screaming warnings into deaf ears.
-Bill Mumy guest stars.
21) Alpha
An engineered assassin project isn’t creating the remorseless killer the creators hoped for, but before they can fix her she escapes. She turns up as Tina’s new lab assistant, and she’s in great need of help as even her assassin abilities can only do so much against the team of evil government agents.
22) Trial of the Trickster
Trickster is getting his day in court, and it’s a circus. A girl wanting to be Prank springs him, and he sets out after Megan and the Flash. Having Trickster on the loose is bad enough, but when he brainwashes Barry the pair goes on a destructive rampage throughout the city.
-Mark Hamill returns as the Trickster this time with sidekick Prank.