"Stand down. Joseph is dead."
"Well...I didn't see that coming.
—Eva McCulloch and Nash Wells
"Success Is Assured" is the nineteenth and final episode of the sixth season of The Flash, and the one-hundred-thirty-third and most recent episode overall. It aired on May 12, 2020.


Barry considers a risky plan to save Iris from the Mirrorverse. Ralph attempts to stop Sue from making a grave mistake that could destroy her life.[src]


Eva McCulloch's protective suit

As Eva McCulloch dons a new suit to accommodate for years in another dimension, "David" tells Rob that he has chosen to be with his "mother", not him. The two decided that all that Joseph Carver has must be destroyed before he dies.

Team Flash has a meeting at the police precinct, since Barry Allen doesn't want to add his job to everything else he has recently lost. During the meeting, Ralph Dibny reveals the Black Hole diamond he got from Sue Dearbon; Allegra Garcia notes that it emits radiation. Focusing the emissions, she helps the team to find a warehouse that Black Hole uses for storage. When the Flash and Elongated Man arrive, they see "David" has killed the security guards and is about to set the place ablaze. "David" succeeds.

The game plan now changes to the protection of Carver from his deranged wife. Caitlin Snow cannot participate though, as Carla Tannhauser has arrived to take her daughter away to heal. The two decided to heal their relationship as Frost wants to be closer to her as well.

At a Black Hole safe house, Eva captures Sunshine, Ultraviolet, and Dr. Light, and transports them to the Mirrorverse.

In the Mirrorverse, at its version of S.T.A.R. Labs, Iris West-Allen and Kamilla Hwang discuss how to find David Singh; though Kamilla has not adapted, Iris begins to itch and, every-so-often, begins to see what appears on reflective surfaces.
Team Flash prepare to fight the Black Hole metas

With his meta-humans gone, Carver goes to Team Flash for protection. At the precinct while they wait for an A.R.G.U.S. transport, the team and Carver encounter "David"; he proposes to exchange Iris for Carver. As Barry listens, Nash Wells pushes "David" away and teleports the team back to S.T.A.R. Labs. He argues with Barry that he is beginning to act less than heroic, citing that Barry was willing to kill him in order to be rid of Eobard Thawne.

Meanwhile, Sue has reunited with her parents, but has become a Black Hole operative to keep them safe. When Team Flash takes Carver to McCulloch Technologies to protect him there, Sue is present, plotting to double-cross and kill him herself.

Eva infiltrates Joseph's panic room

Suddenly, Eva McCulloch's team arrives; they have willingly switched sides. Carver sends his security guards to assault the women causing a melee that eventually brings Team Flash into the fight. The Flash is protecting Carver from Eva; Eva succeeds in killing Carver. With Carver dead, the fight is over.

Iris suddenly disappears

Carver's death causes Joe West to no longer need to be in witness protection; he and Cecile Horton join the team as Barry feels bad about his failures.

Sue is jubilant that Carver is dead; Ralph informs her that Eva had a press conference, blaming her for Carver's death.

In the Mirrorverse, Iris has a moment of clarity and locates David. Suddenly, as Kamilla panics, Iris glows and disappears...



Guest starring



  • The title references the mantra frequently repeated by the Reflections to Eva McCulloch which in-turn was inspired by the phrase from the Wright brothers.
  • Due to the COVID-19 pandemic,[1] Grant Gustin revealed in an interview with TVLine that this episode serves as the sixth season finale.[2]
    • Also, the episode has a different cliffhanger than planned, as the original season finale was going to have an Eobard Thawne-based cliffhanger for the next season.[2]
    • Since the season was cut short, this marks the first season finale where Carlos Valdes (Cisco Ramon) is absent.
      • This probably notes that during the events of this episode, Cisco was possibly at Atlantis trying to get the component for the perpetual motion machine in which in the previous episode ("Pay the Piper") it was mentioned that the component was located in Atlantis.
    • At the end of the episode, the "To Be Continued.." was shown to prepare for the next season.
  • This is the first season finale where the main season antagonist was not defeated by Team Flash; however, this is due to this episode not originally being written as a season finale.
    • This is the second season finale where a major protagonist doesn't get killed. The first was the Season 4 finale "We Are The Flash".
      • However, Iris appeared to either dissolve or get transported to a new location, meaning her status is currently unknown.
  • This episode marks the final appearance of Hartley Sawyer (Ralph Dibny) on the show due to being fired on June 8, 2020 as a result of offensive tweets resurfacing.[3]


  • Nash Wells shouldn't make an appearance at CCPD because the police who are working there could have recognized him as Harrison Wells because of what happened in Season 1 in which Eobard Thawne was supposed to turn himself in because of his crimes such as the creation of the Particle accelerator and the murder of Nora Allen.
    • However, it's possible Barry could have explained Nash being Harrison Wells' twin like he did with Hartley, though it is unknown when he could have done this.
  • In the mirrored McCulloch Technologies, the secret room behind the mirror is accessible by a button on the right hand side. However, in the real world, the button is still on the right when it should be on the left.




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