Flash Barry (Grant Gustin, left) and Joe (Jesse Martin, right) finally came face to face with Barry's mother's killer in the midseason finale of "The Flash" Season 1. Photo: The CW

It was the midseason finale of “The Flash” Tuesday and Christmas time in Central City. Fresh off the “Arrow” and “The Flash” crossover, Barry (Grant Gustin) would come face to face with his most dangerous criminal yet in episode 9, “The Man in the Yellow Suit” -- the man who killed his mother.

The episode began with Barry helping Joe (Jesse Martin) and Iris (Candice Patton) decorate Joe’s Christmas tree. However, Joe is quickly called into the station leaving Barry and Iris alone to exchange presents. Barry gives Iris a replica of her mother’s wedding ring, but the tender moment was interrupted when Eddie (Rick Cosnett) came to her up.

Barry, on the other hand, paid a visit to S.T.A.R. Labs with some eggnog where Dr. Wells (Tom Cavanaugh) was a little grumpy about the holidays considering that was when the accident happened with particle accelerator.

Meanwhile, on Eddie and Iris’ date, Eddie questioned if Barry had feelings for her, but she denied that they are anything more than friends. Eddie followed that up with another question -- if she would move in with him. Iris said yes.

Back at S.T.A.R. Labs Caitlin (Danielle Panabaker) was spooked in the parking garage by a mysterious meta-human who was consumed by flames. She appeared to recognize the man.

Meanwhile, a lab across town, Mercury Labs, was robbed by another meta-human with eerily similar powers to Barry. The next day, as Joe and Barry surveyed the crime scene, where a few guards were dead, a witness revealed that all he saw was a yellow blur, just like the night of Barry’s mother’s murder. Joe finally confessed to Barry that his mother’s killer had returned.

At S.T.A.R. Labs, Dr. Wells surmised that the killer was likely trying to steal rare Tachyon particles at Mercury labs that could bestow unlimited powers if harnessed properly. Dr. Wells and Barry paid a visit to Mercury labs to see if they could borrow a sample to use as bait, but Dr. Tina McGee (Amanda Pays), an old rival of Wells’, refused.

Elsewhere, Caitlin visited Iris to question her about the fire meta-human. Iris had written about him in her blog, but did not have much new information to give Caitlin. Caitlin later confessed to Cisco (Carlos Valdes) that she believed that the mystery man was her dead fiancé, Ronnie Raymond (Robbie Amell).

Later, Iris visited Barry to see if he had any problem with her moving in with Eddie. She seemed to be probing him to see if he had any feelings for her, but he lied and said he did not.

After Iris left, Barry got another visit -- from his mother’s killer. Barry angrily asked why he did it, but the stranger -- whom Cisco dubbed Reverse Flash -- told Barry he would have to catch him first. Barry and Reverse Flash took off on a supersonic chase, but Reverse Flash, who was even faster than Barry, was only toying with him.

Unable to catch Reverse Flash, Barry went back to Dr. Wells and Joe. Joe and Barry went to Mercury Labs where with a little more coercion they obtained a Tachyon sample. They set up the trap using a force field Dr. Wells made, but Joe and Dr. Wells told Barry they did not want him around to see his mother’s killer caught.

Meanwhile, Cisco helped Caitlin track down Ronnie in the basement of S.T.A.R. Labs, but her former fiancé was not happy to see them, lashing out at them and insisting that he was not Ronnie, calling himself Firestorm before fleeing in flames.

Barry went to visit his father (John Wesley Shipp), devastated that he had been unable to catch Reverse Flash and clear his father’s name. However, Barry’s Dad told him to let it go, saying that the night Barry’s mother died took enough away from their lives and to not let it consume him now too.

Barry left the prison and went straight to Iris, finally confessing his love for her, leaving her shocked and in tears.

Back at S.T.A.R. Labs the Reverse Flash fell right into Dr. Well’s trap, but the yellow-suited man did not seem nervous to be captured in the force field. While Joe and Dr. Wells questioned Reverse Flash, who said he was nothing like the Flash, Cisco noticed that the force field was failing. Reverse Flash was able to slip out and pull Dr. Wells into the trap, savagely beating him. Cisco shut it down so Joe could get to Wells, but Reverse Flash just snatched the Tachyon particles and took out the cops in the room. Luckily, Barry showed up just in time to save Joe and Eddie.

However, outside of the lab, Barry was pinned down by Reverse Flash who seemed ready to kill him. Then, Barry was saved by Ronnie, who appeared out of nowhere to chase Reverse Flash away, before disappearing himself.

Back at the station, Joe and Barry talk about what happened and Barry confessed to always being scared of the day he would confront his mother’s killer. Joe told him he would have another chance and to not lose himself in his role as the Flash.

The two returned to a Christmas party at Joe’s house with Iris, Eddie, Cisco and Caitlin. Barry congratulated Eddie and Iris on moving in together, but there was pain on his face.

The bigger reveal at the party was Cisco, who told Joe that when Barry and Reverse Flash were fighting, both red and yellow electricity were flying off of them, just like Barry’s story about the night his mother died. There were two meta-humans in the room that night, not just Reverse Flash.

Cue Dr. Wells, who, of course, gave fans the biggest surprise of the episode revealing a suit identical to Reverse Flash’s in his lab. The doctor is definitely hiding something big, but fans will have to wait until “The Flash” returns to the CW in January 2015 to find out his secret.

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