Barry discovers his powers and puts them to the test, only when he finds its no longer a test but the real thing when he encounters a certain someone.

Mark Mardon, having survived his apparent death during the black-matter explosion, returns seeking revenge on Joe for the death of his brother Clyde... and has the same weather-manipulation powers as his deceased sibling.

Barry and Team Flash come up with a plan to stop Cicada. However, the plan calls for Barry and Nora to travel back in time to gather some key necessities. However, Barry hesitates, concerned about his daughter seeing certain parts of his life. Meanwhile, Sherloque takes his concerns about Nora to Iris, and Caitlin turns up a key asset in the fight against Cicada.