As Barry and the team at S.T.A.R. Labs
work to capture Kyle Numbus, aka The Mist,
a dangerous new meta-human with toxic gas
powers, they revisit the painful night the
particule accelerator exploded and killed
Caitlin's fiance, Ronnie. Meanwhile, Joe
decides to finally visit Henry in jail
after all these years, but things take a
dangerous turn when Kyle shows up looking
to punish Joe for arresting him years ago.
Meanwhile, Iris and Eddie continue to hide
their relationship from Joe.