You'd think Barry has enough problems just trying to out-think the Thinker on The Flash, but in "Fury Rogue," the Flash not only has to face DeVoe, he also has to deal with a surprise villain from Earth-X. In an attempt to get ahead of DeVoe, Barry recruits Captain Cold (or Citizen Cold), aka Leo Snart from Earth-X, to help transport Fallout, the radioactive bus meta meta he encountered earlier in the season. And in addition to Citizen Cold, Barry might be getting a new ally soon, as it looks like the Mechanic might betray the Thinker on The Flash.
After seeing pocket dimension activity around where Fallout is being held, Barry worries that DeVoe is making Fallout his next target, and plans to move him to an ARGUS facility nearby. The only problem is, he's too unstable to move, not without a massive cooling source, one they no longer have since Killer Frost was seemingly eradicated by DeVoe. Seeking a cold source, Barry travels to Earth-X and recruits Leo, who fans will remember fought alongside the Flash in this year's crossover "Crisis on Earth-X" before joining Legends of Tomorrow for a brief arc. Unfortunately, when he brings Leo back to Earth-1, the Earth-X Siren (Laurel Lance), who happens to be a Nazi, follows them. And all the while, Barry thinks that going to Earth-X to recruit help is going to be something unexpected for DeVoe, when in fact the Thinker has seen everything coming.
What DeVoe fails to predict, however, are the emotional effects of Dibny's death. DeVoe predicts that Earth-X Siren will attack DeVoe, Citizen Cold, and Barry to get Fallout, but that Barry will defeat her. Instead, after some taunting from the Thinker about Dibny, Barry freezes, and Siren kidnaps Caitlin, Joe, and Fallout. Stewing about his plan in his pocket dimension lair, DeVoe dismisses Marlize's suggestion that his prediction's didn't come true because he was ignoring emotion. His obsession with rational thought — his own, and no one else's — has made him forget about the emotional drives that others, like Barry, have. DeVoe turns on Marlize for daring to make any sort of statement, telling her to leave the thinking to him.
The Thinker's constant belittling, coupled with his rejection of affection from his wife, are definitely starting to put a strain on Marlize. Though we've seen this before, when the Mechanic realized that he was drugging her with meta tears of happiness and love, only to have her memory erased and the cycle started over, this seems different. Marlize isn't suspecting her husband of deceiving her, she's watching him become corrupt with power, and she's keeping up appearances to his face. At the end of the episode, after Barry, Leo, Cisco, Caitlin, Iris, and Joe successfully get Fallout into ARGUS custody — which, it turns out, is exactly where DeVoe wanted him — DeVoe asks Marlize if she sees now that everything played out exactly the way he thought, no emotional calculations needed, and how his thought should be valued above hers until the Enlightenment, she responds in the affirmative, but when she turns around, there are tears in her eyes.
It definitely looks like Marlize is having second thoughts about her husband's plan. Now that he's attained all the power needed to sustain his accelerated thinking without deteriorating his body, his ego is out of control, and his love of rational thought is chipping away at his love for his wife. Marlize might believe in the cause of Enlightenment, but does she still believe in it if it costs her her husband? Her doubts as well as DeVoe's increasingly abusive behavior towards her could be just enough to push her into the comforting and forgiving arms of Team Flash. At the end of the day, it looks like emotion will be the thing that brings down DeVoe. Whether that act of emotion comes in the from Marlize or Barry or both remains to be seen.