Before Rachel's disappearance in 2013, it is implied that Rachel and Frank were more than friends.
Life is Strange
It is heavily implied from the evidence in David Madsen's files and in the letters that Max Caulfield finds in Frank's RV that Rachel was in a romantic relationship with Frank. However, this relationship is something that was kept hidden from Rachel's close friend, Chloe Price. The reason for keeping Frank's closeness a secret from her close friend has been speculated by many fans as Chloe either having been intimate with Rachel in the past and still harboring feelings for her, or having carried unrequited feelings for a while and Rachel perhaps being aware of this. Chloe could also just be an extremely intense person resulting from attachment/abandonment issues or just very possessive and prone to jealousy.
In Episode 2, Frank is seen wearing a bracelet that belonged to Rachel. The possession of this bracelet means so much to him that he pulled a knife on Chloe when she tried to take it from him in anger, feeling that she has more right to it than he does.
In Episode 3, Frank immediately recognizes that Max is wearing Rachel's clothes and insults Max for wearing them, telling her that Rachel looked beautiful in them whereas Max does not. He describes Rachel as a natural beauty.
Nathan Prescott believes that Rachel was only into Frank for his "stash" (drugs) and let him take pictures of her in return. He thinks Frank is a "dumbass" for carrying around a picture of Rachel like it was love that she felt for him. It can also be learned from Nathan that Frank took a "weird blood oath for Rachel". It is unknown what this entailed as no further details are learned about this. Nathan also tells Max that "everybody knows Frank is a liar and a loser. Even Rachel did..."
From David's surveillance on Rachel, it is learned that Rachel was cutting class for a week, avoiding her dormitory, and meeting with Frank. She was picked up by police from Blackwell Academy one afternoon for possession of a controlled substance after being witnessed by campus security (David Madsen) trying to hide or secure a suspicious medical bag. She responded to officers with threats and denials. Her bag was found to contain various illegal pharmaceuticals. Frank tells Max in the diner that he "gave Nathan some prescription meds... as a friend", so Frank is a likely source of the pharmaceutical drugs that Rachel possessed. Additionally, we can learn from an unfinished letter to Chloe in the hideout at the junkyard that Rachel was having secret liaisons with Mark Jefferson[note 1] who uses illegal pharmaceuticals on his photography models. The following letters, written by Rachel, are discovered by Max inside Frank's RV:
Hope you read this first thing in the morning. Sorry about last night. I was being a monstrous bitch and took it out on you. And poor Pompidou. There's a lot of weird shit going on in my life and sometimes I feel like I'm never going to get out of Arcadia Bay. Thank god for you. You're one of the best things I have here and I smile when I think of us together. Let's just drive out of here forever,
Love u always
- (heart) RA -
That was not cool what you did. And don't blame the drugs. You actually scared me and I thought you'd never chill out. I've never seen you act that way and the next time will be the last. I'm a Leo and we don't look back. I care about you, us, so maybe we need to break our routine.
- xo RA -
When Max examines these letters again during her investigation with Chloe in Episode 4, she says: "So what happened to Rachel after this? She dumped Frank, but I don't think he would hurt her." . . . "There’s no doubt she loved him in some way...."
Frank calls Rachel his "lioness", which may have something to do with her saying she is a Leo in one of her letters to him.[note 2]
At the beach, Frank tells Max, "When Rachel vanished, I pretty much lost everything... " and tells her that she and Chloe don't know Rachel like he did. He also says that he "can't stand not knowing where she is... not hearing her voice... or her laugh... anymore." It is clear from the way Frank talks about Rachel that he loved her.
A jealous confrontation between Chloe and Frank can also occur at the beach which sheds further light on Frank's opinion of Chloe being a thorn in the side of his relationship with Rachel:
Chloe: "I loved her, asshole. And she loved me. I know that."
Frank: "Chloe, you don’t know shit. You were part of her problem. Always trying to take her away from me... Always!"
This seems to suggest a possessive jealousy from Chloe who was perhaps trying to keep Rachel and Frank apart. Either Chloe knew something was going on and was in denial, or she was trying her best to keep them apart in the fear that something could happen which would cause her to lose Rachel's attention/affection.
"Rachel… Oh, God. She was the one good thing in my life, Max. I know she was too young, and... I expected her to leave me, just… just not how it happened. I would never have stopped her from going after her dreams."
He will also make an automated comment to himself that suggests how seriously he misses Rachel and how he was considering leaving Arcadia Bay just to find her: "I was just about to drive to Los Angeles too..."[note 3]
From further comments in the diner, it appears that he harbored some jealousy over Rachel's closeness with Chloe (whatever that closeness entailed). This is evident from his words to Max: "I knew Chloe and her... were close... I was jealous..." . . . "Rachel cared about a lot of people... especially Chloe..." . . . "But, uh... now I see why Rachel dug her... and Chloe was man enough to ask me for help after all that shit we went through."
Frank is devastated if Max chooses to tell him the truth about the cause of Rachel's death as he will learn that he indirectly had a hand in it. Regardless of how deeply Rachel felt for him, it is clear that Frank loved her.
Before the Storm
It is unknown if Frank is familiar with Rachel (although he does already know Chloe at this point, due to her purchasing pot from him every month). In the run-down building that has been converted into a punk club, Frank intervenes to protect Chloe and Rachel when they are being chased by two men in the club; he blocks the two men, allowing Chloe and Rachel to enter the mosh pit where the band, Firewalk, is playing.
In the second episode, Frank does not have any interactions with Rachel. However, Chloe notices a woman exiting Frank's RV who is the same woman she had seen kissing Rachel's father at Overlook Park the day before. This woman is later revealed to be Rachel's biological mother. She appears to be part of a criminal network that Rachel's father, a district attorney, has an interest in. No further information is known about her at this time.
In the third episode, when Chloe and Rachel meet with Frank in the junkyard before Damon Merrick arrives, a subtle exchange of looks occurs between Frank and Rachel, which could imply some attraction to one another or perhaps some suggestion of previous relations. After Frank arrives and compliments Chloe's car, a moment of silence occurs as Frank looks at Rachel and Rachel looks away from Chloe. Chloe then breaks the silence and the game continues. It seems intentional but very subtle in how the scene is portrayed.
- During the Life is Strange Livestream, the developers confirmed that Rachel was in fact in love with Jefferson and that the letter to Chloe in their hideout actually referred to him.
- Rachel's birth date on her Student Information Sheet is July 22nd, which makes her zodiac sign Cancer, not Leo.
- It was Rachel's dream to seek fame and fortune in Los Angeles, and aside from her plans to escape to there with Chloe Price, her dream also seemed to be known by others in Arcadia Bay, such as when Jefferson says that "Los Angeles would have killed her anyway" and when a truck driver says that Rachel had asked him once if he would drive her to Los Angeles.
- See Chloe and Rachel's relationship page for more.