|Location||Cape Girardeau, Missouri|
|Episode(s)|| 1.13 Route 666
4.18 The Monster at the End of This Book (mentioned)
Dean and Cassie met and were romantically involved for a couple of weeks while Dean was doing a job near her college campus in Athens, Ohio. Cassie broke up with Dean after he told her about hunting.
After the death of her father, Cassie places a call to Dean seeking his help as she believes the death to be supernatural in nature. When Sam and Dean arrive in Cape Girardeau, Missouri, Cassie relates to them what happened to her father. She tells them that her father said he was seeing thing, and that a black truck was following him, and that it would "appear and disappear." She tells them that this black truck had caused the deaths of her father and his friend Clayton Soames, driving them off the road. Soon after talking with Sam and Dean, Cassie's editor Jimmy Anderson is also run down by the truck. Cassie goes to Mayor Harold Todd in an attempt to get him to close that section of road down so no one else will be hurt, but Mayor Todd remains unconvinced by her pleas. After Cassie accuses him of not making it a priority because the victims were black, he tells her he's the last person she should call a racist and to go talk to her mother.
As Cassie is preparing the paper's tribute to Jimmy, Dean shows up and the two have a conversation about their past relationship, and where it all went wrong. When Cassie tells Dean that she thought he told her that story because he wanted to get rid of her, he tells her he didn't, and was hurt by her actions. Cassie and Dean apologize to each other, and the two have sex.
Later, Dean and Cassie are at the newspaper office researching when they come across information on Cyrus Dorian, and learn that Mayor Todd bulldozed the old Dorian home the day before Clayton Soames was killed. Later that night at Cassie's home, she hears a revving engine outside. Headlights shine through the slats of the blinds and she hurriedly closes them. The truck starts making passes at the house and Cassie, terrified, runs from room to room closing the blinds. She races for her phone and calls Dean. When Sam and Dean arrive, Cassie's mother ends up telling them all what really happened with Cyrus Dorian and Cassie's father all those years ago.
After Sam and Dean dispatch Cyrus Dorian's spirit, Dean hopes there may be some possibility of renewing things with Cassie, but she disagrees, saying she 'doesn't see much hope for them'. Despite this, Dean insists that he will return eventually; "Cassie, I'll see you, I will."
When Dean is reading one of the Supernatural books, he mentions, "Everything is in here. I mean everything. From the racist truck to – to me having sex." These events happened during the time he spent with Cassie.