“Subject 9” is episode fourteen of season four of The Flash.
In the previous episode, “True Colors”, Barry was cleared of killing DeVoe after DeVoe – Ralph – turned up alive. He’s arrived back at the CCPD, but isn’t welcomed. Captain Singh tells him that some people think he shouldn’t be back on the force. Allegations are treated as facts and some people don’t believe DeVoe is really alive. They’re both right and wrong. He’s not firing Barry, but the new mayor suggested he take an indefinite leave of absence. Barry asks the captain when he thinks Barry can come back. When everyone believes DeVoe is alive.
Back at S.T.A.R. Labs, Caitlin and Iris reassure Barry. There are still four bus metas to find, too. Ralph and Cisco arrive after being at the bus depot, collecting the lost and found for the bus the metas were on. There’s a CD by an Izzy Bowen on it, and Cisco vibes on it. He sees Izzy at The Busted Saddle Saloon, playing a gig.
Barry and Ralph head there. DeVoe, now in Becky’s body, and Marlize are watching. DeVoe doesn’t think Izzy is ready, then collapses. The accumulated dark matter from every body is wearing out Becky’s rapidly. DeVoe will need to take Izzy’s. They see Ralph and Barry arrive.
After the gig, Barry and Ralph explain to Izzy that she’s in danger, and someone is going to come after her. She asks why and is told that everyone that was on the bus she was on has powers. Izzy asks if they’re there to protect her. Something like that. Izzy doesn’t think that’s necessary. And blasts them both with a sonic pulse.
Harry has returned and bumps into Cecile whilst getting coffee. She’s constantly tired, because she can hear Joe’s dreams whilst asleep, and they’re keeping her awake. Harry thinks he might be able to help.
The team can’t find Izzy and Cisco asks Ralph how he would as a PI. Ralph would check her website. It turns out no-one has done that. She’s still in town.
Cisco, Barry and Ralph head to find Izzy, all in costume. They say someone is going to hurt her. She asks who and DeVoe appears. DeVoe says they aren’t smart enough to stop him 9her?) from getting what he wants, and he wants Izzy. He uses Kilg%re’s power against Cisco and takes all three of them down. Then Izzy blasts DeVoe away and Marlize shows up and they both disappear.
Izzy has just hurt DeVoe and Barry wants to train her. He reveals who they are in the process to try and gain her trust. And Ralph, despite a hatred of country music, seems to really like Izzy. DeVoe needs new bodies, because the extra dark matter from each meta whose powers he takes is wearing them out faster. And it may well be affecting his personality as well.