The team recruits Harrison Sherloque Wells to help them catch Cicada, who Nora reveals is unstoppable in the future. Caitlin and Ralph confront Caitlin's mother, who denies forging her husband's death certificate. Sherloque pinpoints Cicada as David Hersch, but is proven to be wrong when Cicada attacks Joe, looking for Vibe. He reveals that on 37 other Earths, Cicada has the identity of Hersch. As a result of Nora's tampering with the timeline, however, his identity on Earth-1 is different. Additionally, his reign of terror has begun earlier than expected. Caitlin and Ralph break into her mother's files, where they find a suicide note from her father. After Cisco shows up, Cicada stabs him, breaking his arm. Barry arrives, but is easily defeated. After Nora enacts her plan to drive Cicada off, it seems as if Cisco has been killed. It is revealed that Cisco used a breach machine instead of his hands to escape. With the public and Cicada believing that Vibe is dead, Sherloque agrees to stay and help the team fight off the dangerous meta. Caitlin traces a message and realizes that her father, Thomas Snow, is asking her to come looking for him. A mysterious individual watches her through the STAR Labs security cameras. Cicada is revealed to be a father of a daughter who is in a coma and not healing. Nora agrees to stay with her parents, despite her seemingly strained relationship with Iris. Sherloque begins to suspect that Nora is not in 2018 for the reasons she says she is.