Barry and the team go after the Mist, who possesses toxic gas powers, and they reflect on the night Caitlin's fiancé died. Meanwhile, Henry gets a long-awaited visit from Joe, and Iris and Eddie continue to keep their romance a secret from Joe.

The Flash battles Captain Cold after the villain is involved in a robbery and plots to steal the Kahndaq Dynasty Diamond.

After a bomb explodes downtown, the army rolls in and takes over. When Joe learns Iris is writing about 'The Streak' and tries unsuccessfully to have the story stopped, Barry decides to have The Flash pay her a visit.

The Flash faces a new meta-human named Tony, who can turn himself into girded steel at will.