"Things You Can't Outrun," the third episode of The Flash season one (2014), follows Barry Allen and the S.T.A.R. Labs team as they neutralize Kyle Nimbus, a metahuman capable of transforming into toxic gas. The episode explores themes of grief, establishing the team's metahuman prison and featuring flashbacks to the particle accelerator explosion that resulted in Ronnie Raymond's death. For a comprehensive summary, visit Arrowverse Wiki .