Grace-Pete Relationship is the romance and friendship of Pete Martínez and Grace Gardner. They first met in Pilot, and they're good friends. They kissed in Hell Week, but Grace ran out the day after when she saw that Pete had the red devil costume in his dorm room. In Chainsaw they made up and are friends again. They are working together to solve the mystery of the bathtub child born in 1995.
In Beware of Young Girls, Grace and Pete kiss again even though Grace had originally said she wanted to focus on finding the killer. Pete confirmed their romantic relationship in Thanksgiving, but their relationship ended after Pete was murdered by the Red Devil in Dorkus.
HistoryKappa, saying that it's a dangerous house. Chanel Oberlin interrupts their conversation and says to Grace that Pete got a little too obsessed with her last year and that she had to get a restraining order against him. Pete explains that he was a freshman with a huge crush on her, then accuses Chanel of intentionally leading him on. Grace doesn't react well at first but when she hears Chanel's reasoning for leading him, she seems to ignore it. Pete tries to warn her one more time before she leaves but it fails
After Agatha Bean's death, Grace later confesses to Pete what that Chanel did it, but Pete already admits that he saw them take the body and that he is the reporter of the school newspaper, The Sentinel. Grace offers to be his eyes and ears inside the house so they can destroy Chanel and expose what she did. They then go to the freezer to examine the body, however Chanel and her boyfriend Chad Radwell arrive and discover the body is missing.
After learning that Chanel is the only one with a key to the secret door, Grace tells Pete about it, who says that people has been whispering for years that the Kappa house has a really dark secret. This makes him think that Dean Munsch's office may have some archives that can explain that secret, so they both think at the same time that they will have to break in.They start kissing passionately but Grace stops him, saying that they can't kiss if there is a killer in the campus of Wallace University. They both agree that she will break into that secret door at Kappa house and he will break into the dean's office.
When Pete is attacked by the Red Devil after finding names linked to Kappa's past, he meets up with Grace in his dormitory. Grace tells him about the Kappa legend and he, shirtless, shows her the names that he wrote on the sheet. Grace opens the closet to give him something to put on, but discovers the Red Devil costume, which happens to be the mascot of the university. Grace freaks out and asks Pete about his age, he answers that he will turn 20 in a month. Scares, Grace leaves the room because that is the exact same year that the baby would have, and thinks that Pete might be the killer.
Grace visits Pete and apologizes for ignoring his messages, and both tell each other new clues they found, including a girl who was 2 credits away from graduating 20 years ago named Mandy Greenwell.
When Grace's father, Wes Gardner, rings Grace asking her where she is, she lies and says she's at the library. In reality, she is with Pete at the gas station.
Grace and Pete drive to a trailer which is owned by Mandy Greenwell who tells them about what happened 20 years ago. In a flashback to 1995, Mandy and her sorority sisters are forced to wear hoods while Cathy drives to a location to bury Sophia. While digging, Cathy says they should leave the university immediately and never contact each other again. They then throw her body in the hole. Back in the present, Mandy says one of the sisters killed herself, another was institutionalized and another made it into FOX News. She then reveals that the bathtub baby is a girl, which shocks Grace and Pete massively since they believed the child to be male (and actually thought it was Chad Radwell specifically).
When Grace is leaving the building after confronting her father about if she is the baby in the bathtub, she receives a text from Pete to meet him at 53 Shady Lane. When she arrives, Pete scares her and soon Earl Grey and Zayday Williams scare him. When Grace asks what they're doing there, Zayday says she's having the haunted house charity there. Denise Hemphill appears, startling them and says the house is haunted and she and Pete tell them the story of 'The Hag of Shady Lane', the former resident of the abandoned shack, who took care of the bathtub baby in 1995.
Grace and Pete later attend Zayday's party together, both discovering that the Red Devil's victim's bodies scattered around.
When Cathy and Denise are discussing sleeping with Chad in the former's office, Grace and Pete (along with Wes and Gigi Caldwell) barge in and talk about their search for Zayday. Cathy says she hired an investigator from Secure Enforcement Solutions, which is Denise, which makes everyone groan because they're serious about finding their friend.
Grace, Pete, Wes, Gigi and Denise find The Red Devil's secret lair, where the Red Devil turns the power off leaving them in total darkness. They split into two teams; Grace, Pete and Wes on one side and Gigi and Denise on the other. When Gigi tazers the Red Devil, he escapes which disappoints both Grace and Pete.
Although Pete doesn't physically appear in the episode, him and Grace are mentioned quite a lot. After three students are murdered in the Kappa house, Chanel questions the suspicious nature of Pete not being there, which she aims towards Grace since she knows they're close. Grace defends Pete and tells them that he told her he was studying.
Pete later texts Grace telling her that he has finished studying.
When Gigi mentions Feather McCarthy and Cathy's rivalry to Grace, she and Pete decide to meet up with Feather and question her about the Dean (Cathy). Feather openly admits that whatever is happening; Cathy is behind it. After Feather has revealed why Cathy is evil, Pete asks if she will go on record for a source and she willingly believes which makes both him and Grace happy.
After hearing Feather's story, Grace and Pete investigate and manage to link Cathy Munsch to many of the other murders that happened on campus, and so, Cathy is suspected to be the Red Devil and is taken to an insane asylum. Grace and Pete share another kiss, thinking the whole Red Devil case is over, and Cathy Munsch sends Grace a text, asking her and Pete to come and visit her.
The following day, they visit her in the asylum, where she reveals she can't eat bologna because it would put her into anaphylactic shock. It occurs to Pete that the killer made a sandwich at the scene and had taken a bite out of it and they decide to find out what kind it was. Pete and Grace return to the scene to find out that it was a bologna sandwich, and thus, decide Cathy couldn't have been the killer.
After they meet up in The Grind, Grace meets up with Pete to do some investigating on Sophia Doyle. Pete tries to find information online, but he's not having much luck. Grace gets aggravated and says that she knows Sophia is her mom and that she's had a feeling that she was the bathtub baby ever since these murders started. She says she used to speak to her mom when she was little, and that she felt her presence. Grace says she was always a benevolent spirit, but there was some kind of sadness there that was keeping her from moving on, as if she had some unfinished business. That's why Grace came to Wallace and joined Kappa because she wanted to finish what her mom started, and in order to do that, she has to find out who her mom is and stop the madness that is going on at Wallace. Pete suggests that since they can't directly find Sophia, they should look into the Hag of Shady Lane, since she's the one who took care of the baby before disappearing altogether. He thinks they should visit the only logical place where crazy people go; the insane asylum.
At the asylum, Pete and Grace approach the woman who "paints them all". They ask her if she remembers a girl from about 20 years ago who wailed a lot and maybe had a baby with her. The lady hands them 2 paintings - one of Gigi, and the other of Gigi wearing a black cloak and holding 2 babies - a boy and a girl. Grace makes the connection that Gigi must be the Hag of Shady Lane and her and Pete run out of the asylum with the paintings ready to confront Gigi.
When everyone is accusing each other of being the Red Devil at the Kappa Thanksgiving dinner, Pete decides to turn-up with a lot of evidence to prove one of them is the killer, and he thinks it is no other than his girlfriend's father; Wes Gardner. Pete tells a story he has compiled of evidence he has dug up, claiming Wes is the killer. Pete reveals that, by bribing a government official with drugs, he discovered that Wes was Boone Clemens' father, and thus, the father of the other bathtub baby.
Pete and Grace are present and sitting together when the dinner is served and are both seen screaming when Gigi Caldwell's decapitated head is discovered.
At the end of the episode, Grace tells Pete she's willing to have sex with him, but he refuses, saying he doesn't want her first time to be with a murderer.
Immediately following the events of the last episode, Pete explains that he was the one who killed Roger, and Grace becomes furious with him. As he's about to reveal who the Red Devil killer is, the Red Devil bursts into the room and stabs Pete to death.