'Criminal Minds' Season 12 Episode 20: Walker Takes the Lead in New Case

Facebook/CriminalMindsWalker takes the lead in the upcoming episode of "Criminal Minds."

Walker (Damon Gupton) will take the lead in an investigation involving a close friend in the upcoming episode of "Criminal Minds"

In the episode titled "Unforgettable," the synopsis (according to Spoilers Guide) reveals that the unit will be tapped to probe the mysterious deaths of several federal government employees. A preliminary investigation shows that they all died due to heart attack. When it is identified that one of the dead men is Walker's friend, he becomes more invested in the case. No matter how they analyze the incidents, the agents cannot fathom how everyone expired because of only one cause. What are they missing?

Meanwhile, time is ticking for Reid (Matthew Gray Gubler). He will finally learn the date of his trial. He will be tried for the murder of Nadie Ramos (Ani Sava). The agent's predicament keeps on becoming more complicated. After the nightmare he has experienced in prison, Reid is at the end of his tether.

In her February interview with TV Guide, showrunner Erica Messer could not promise that the arc would be a happy one for the agent and his sick mom. If there is anything that viewers can expect, it is that Reid will not be getting out of this scary scenario for a while.

"But at the same time, every time you look at Reid, you see he was just trying to do the right thing for his mom. That is at the foundation of this whole story. It's like you're cheering on this hero because he did something you might do to help a loved one and because he's an FBI agent and because there's a crazy psychopath targeting his team and because we're a TV show, stuff went super sideways," the EP teased.

"Criminal Minds" season 12 episode 20 will air Wednesday, April 26, at 9 p.m. EDT on CBS.