4. The Elongated Journey Into the Night (October 31, 2017)
>Cisco is shocked when Gypsy's father, legendary extradimensional bounty hunter Breacher (guest star Danny Trejo), shows up on Earth-1. Breacher takes an immediate disliking to Cisco and decides to hunt him. Meanwhile, a new case leads Barry to cross paths with his old nemesis, Ralph Dibny (guest star Hartley Sawyer), an opportunistic meta-human private detective with the power to stretch his body
5. Girls' Night Out (November 7, 2017)
>Having received an ominous threat from her old boss Amunet Black (guest star Katee Sackhoff), the leader of an underground black market for supervillains, Caitlin fears that her past as Killer Frost may be back to haunt her. Felicity Smoak (guest star Emily Bett Rickards) comes to Central City to help the girls celebrate Iris's bachelorette party, while Cisco, Joe and the guys take Barry out for a night on the town.
6. When Harry Met Harry (November 14, 2017)
>Harry searches for a new purpose now that Jesse has come into her own as a heroine and no longer needs his guidance
7. Therefore I Am (November 21, 2017)
>Barry comes face to face with The Thinker and his nefarious plan to fix all that he deems wrong with the world.
8. Crisis on Earth-X (November 28, 2017)
>The wedding preparions of Barry and Iris are interrupted by the arrival of The Ray (guest star Russell Tovey), a freedom fighter from a parallel universe known as "Earth-X", where Nazis have won World War II and conquered the world. The Flash must then rally his allies, including Green Arrow (Stephen Amell), Supergirl (Melissa Benoist) and the Legends of Tomorrow, to battle their malevolent doppelgangers, the Reichsmen, who have been sent to preven The Ray from succeeding in his mission.