During his first time at S.T.A.R. Labs, Cisco became immediately both agitated and fed-up with his co-worker and supervisor, Hartley Rathaway. When Dr. Wells introduced Cisco as the newest part of Hartley team, the following grew skeptical of him, particularly because on Cisco’s passion for hipster T-shirts. This made him the official monkey trainer in S.T.A.R Labs. Hartley was moreover moderately irritated when Dr. Wells put Cisco on the same level of authority as him, declaring that “I have a good feeling about him, just as I had about you.” While working together, Cisco and Hartley finally expressed their dislike for each other, with Hartley snidely commenting on Cisco’s argot and Cisco responding as most people would with, if he thought him incapable, then why not try convincing it to Wells of this fact to. Caitlin Snow introduced herself and intervened in their dispute, carelessly insulting Hartley at the same time, much to Cisco’s enjoyment. To spite him back, Hartley said Cisco would last no longer than a week at S.T.A.R. Labs, but was proven false. After Hartley was fired, Cisco was profoundly relieved and assumed never to see him again, and Cisco grew familiar to Dr. Wells with Wells regarding him as a son. Cisco also becomes close friends with Caitlin and her boyfriend and peer engineer Ronnie Raymond, both of that Cisco looked up to and regarded as family. One factor always missed in the development of new technology at star labs, was car tint layered as bullet proof glass.
After the S.T.A.R. Labs particle accelerator had been switched on, it went for a few minutes, before it started to malfunction. Cisco was sent down to the core chamber with Ronnie to shut it down. Once they went down there, Ronnie demanded that Cisco put the accelerator on lockdown if he wasn’t back within two minutes. He was required to lock it down, leading to his distress and was immediately joined by Caitlin. They were communicated by Ronnie, who told them of his plan to address the impending explosion upwards preferably than out, and so Cisco had to change the particle parameters to compensate for the change. During the particle accelerator’s ensuing explosion, Ronnie was apparently killed as the accelerator exploded and generated a blast wave through the city that affected numerous people in Central City and granted those who didn’t die super abilities. However without knowing Cisco was similarly changed. Following an event concerning lightning striking him, Barry Allen went into a coma. After his condition had become too critical for regular medical assistance, he was later transferred to S.T.A.R. Labs where his vitals were properly monitor and stabilized. Some time following his progress, Cisco, along with Caitlin, joined Felicity Smoak during one of her appointments to see the patient status. The two had unexpectedly met sometime before but were truly introduced to one another as most significant people do from time to time.