The show opens, with a collaboration between The Flash (Grant Gustin) and Dr. Wells (Tom Cavanagh), which ends in the arrest of some motorcycle criminals. When Barry returns to STAR Labs, Cisco Ramon (Carlos Valdes) suggests celebrating with a picture. Despite initial arguments, Barry takes the picture, with his mask off. Barry runs into Iris West (Candice Patton) at home, before Joe (Jesse L. Martin) offers her some spaghetti, before she insists she must get home to help Eddie (Rick Cosnett) paint. Joe tells Iris someone from Central City Picture News called for her. Iris gets a job offer with the news agency.
Harrison returns home and receives a threatening phone call, before his home is ransacked by the Piper (Andy Mientus). Joe and Barry arrive to investigate Harrison’s home. Caitlin Snow (Danielle Panabaker) and Cisco also arrive. Wells doesn’t seem too worried, as he heads off to make hotel reservations. The show flashes back two years and shows Wells playing chess with Hartley Rathaway. Cisco enters and is introduced to Hartley, who insults his t-shirt. After Cisco leaves, Hartley questions Well’s hiring decisions.
Barry puts the glass in Well’s house back together and discovers there wasn’t a point of impact. Wells agrees and admits he knows who is responsible, before pinning it on the prodigal son, Hartley. Wells tells everyone about Hartley coming out to his parents, which turned them against him. Everyone agrees Hartley was a jerk. Wells refuses to provide details of the disagreement, which made Hartley seek revenge against him. The show flashes back again and shows the introduction of Caitlin and Cisco.
Iris heads to work, where Eric Larkin (Tom Butler) introduces her to everyone. Iris offers an idea for a news article, but they assign her to writing stories on The Flash. Joe speaks with Barry and insists Wells could be hiding something. The Pied Piper begins to destroy the Rathaway Industries building, when The Flash arrives. Pied is subdued, but he reveals he knows Wells’s secret. Barry takes Pied Piper to the lab. Hartley spars back and forth with Caitlin and Cisco, before Wells enters. Barry listens in on their conversation. Hartley tells Barry that Harrison will turn on him in a flash. Hartley brings up the deep dark secret, but doesn’t reveal it.
Harrison returns to everyone and tells them that Hartley warned him about the possibility of the accelerator exploding. He insists the reward was worth the risk. Iris is put on the trail of The Flash, while Mason (Roger Howarth) is assigned a corruption story. Mason insults Iris for writing a blog. Afterwards, Iris rendezvous with Barry for a drink. Iris reveals her real reason for being hired and being belittled by her hero, Mason Bridge. Iris thanks Barry for believing in her.
Meanwhile, at STAR Labs, Wells goes missing. Cisco insists Piper could’ve destroyed the whole building, but didn’t, since he likely wanted to get caught. Hartley has escaped. Cisco gets blown unconscious, during the escape, while Hartley attacks Caitlin and takes back his gloves. Wells calls Barry and tells him about Hartley’s escape. Hartley confronts Wells, when Barry enters and checks on Wells. When he finds Wells, Hartley is gone. Cisco has a concussion, but he is fine. Wells insists this was all his fault and Hartley won’t stop, until he pays for his crimes.
We see another flashback of Hartley coming out of Wells’s accelerator. Hartley is fired and escorted out, since he was intent on preventing the risk. Wells holds a press conference and takes the blame for the particle accelerator’s explosion. Meanwhile, Hartley accesses the files, which he stole from STAR Labs. Mason attempts to ask a question, but Wells refuses to answer and asks Iris for a question. She repeats Mason’s question and Wells admits he has no intention of rebuilding the accelerator.
Back at STAR Labs, Piper takes control and tells Wells that the press conference was a sham. Hartley offers one last game of chess between him against Wells and The Flash. Hartley stops traffic, by destroying a toll collection point, before he starts destroying cars. Cisco is able to track him to the Keystone Cleveland Dam. Piper throws a car off the dam, but The Flash saves the woman from the car. Cisco discovers that Piper stole all of Barry’s molecular frequencies from STAR, which prompts Wells to tell Barry to retreat immediately.
Barry removes Piper’s gloves, but he begins controlling Wells, with his mind. The group at STAR begins working to help. Wells sends a frequency, which will destroy Hartley’s weapons. His gloves explode and Barry subdues him. Back at the lab, the group congratulate one another and Wells says he hopes to restore his trust in Barry. Barry gives him the photo, which they took at the beginning of the episode. Barry speaks with Joe about Wells and the press conference. Barry thanks him, in his own way, for raising him. Barry leaves, while Eddie enters and tells Joe he searched Wells’s house, but found nothing. Joe confirms they should continue the investigation of Wells.
Cisco pays a visit to Hartley. Hartley insists Cisco will let him out very soon, since he knows where Ronnie Raymond is. He says he knows what happened to him and how to save him. Meanwhile, Wells is seen in the computer room and is warned the Tachyon output levels have passed acceptable levels. He tells Gideon to increase the levels to maximum. He insists this was only meant to be a temporary fix and the end game is almost here.
The Flash has been consistently good from the very beginning. Each episode seems to offer some type of answer, while moving the plot forward ever so slowly. This one was no different, as a former co-worker at STAR Lab returns. Hartley, or the Pied Piper, was definitely effective thanks to a fun performance from Andy Mientus. Harrison insists he is near his endgame, but will he be found out first? With Barry fully confident of Harrison’s credibility, it will be interesting to see how he handles the potential betrayal. The episode deserves an 8 out of 10.