“Therefore I Am” is episode seven of season four of The Flash.
The episode opens four years ago at Central City University where Clifford DeVoe is teaching a class of uninterested students. Afterwards, his wife speaks to him. DeVoe talks about their plan and about how he isn’t smart enough. She says he’s the most brilliant mind she knows; he needs to be smarter. He’s designed a thinking cap that he wants Marlize to build.
In the previous episode, “When Harry Met Harry…”, Barry and Joe arrived at DeVoe’s house. They’re now inside talking to him, saying they want to eliminate him as a suspect. He’s shown pictures of four metas; he knows the former university faculty member but that’s it. The DeVoes talk about themselves, but don’t reveal anything.
Back at S.T.A.R. Labs, they are discussing whether DeVoe is the one. Barry thinks there’s something off. They agree to check up on DeVoe.
Four years ago, and DeVoe is listening to a news story about the particle accelerator being switched on. Marlize has built the thinking cap, but they can’t power it. DeVoe believes the particle accelerator will provide the power.
In the present, DeVoe is teaching a much more attentive class. Barry is there and speaks to him afterwards, wanting to know where DeVoe was when the accelerator exploded, and if he uses the bus. DeVoe says this feels like persecution. When he looks down at a card Barry gave him, Barry swipes his mug.
Caitlin tests DeVoe’s DNA and says he’s not a meta. Cisco suggests that maybe Barry has wheelchair issues because of the Reverse Flash. Barry is sure DeVoe is hiding something and asks Cisco to vibe the mug. He gets nothing unusual.
Iris speaks to Barry privately, wondering if he’s nervous about the wedding. Barry says Savitar and Kidabra warned them about DeVoe. He could be behind everything.
Four years ago, and the DeVoes are in the audience at the particle accelerator. Marlize asks a question and if ‘Wells’ has perceived every possible outcome of switching it on. He says he has. He also recognises her name because of her husband.
Outside, Marlize says Wells knows the particle accelerator won’t succeed. He’s not just risking an explosion; he wants one. And the fallout of dark matter will cause variants they can’t predict. She wants to delay the plan as it’s too risky; DeVoe is willing to take the chance as the blast is the only thing that will power the thinking cap.
He’s wearing it when the accelerator explodes, and lightning is channelled into it. This nearly kills him, but does superpower his brain. However, it also causes the health conditions that land him in a wheelchair and will kill him.
Barry is convinced that DeVoe is the one they’re looking for, to a degree that makes him look obsessed, probably at least because DeVoe has probably already anticipated what he will do.