Their relationship is sometimes referred to by the fan- given nickname Freffy (taken from Freddie and Effy).Their relationship spanned throughout Series 3 and Series 4.
Effy's father drives her to her first day at Roundview College, but gets into a car accident after driving over a bike in the road. Effy waits silently in the car as her father engages in an argument with an elderly bystander, where she catches the eye of best friends Freddie, Cook and JJ.
During a welcoming ceremony in the auditorium/gym, Effy and Freddie make eye contact again. When Freddie attempts to engage in conversation with Effy at her locker, explaining that he'd like to get to know her, she warns him that his best friends Cook and JJ want the same, which will likely make things "complicated." She then gives him a list of all the things they're not supposed to do in school (drugs, arson, sex, teacher abuse, etc.), and whoever —Freddie, Cook, or JJ (Although JJ is most unlikely to take part) —completes it first before the day's end, she'll grant an opportunity to "get to know" her. In class it's Freddie's turn to introduce himself, and he reveals he met a beautiful girl,referring directly to Effy.
Effy herself gives no indication that she returns his affections until "Pandora"; after she has trashed herself at the crashed pajama party, she notices Freddie and tries to speak with him, but he impatiently brushes her off, irritated both by her affair with Cook and for not looking after JJ (whom he came to collect). He softens when she reveals her parents' decision to split; as he and JJ leave, Effy cries silently.
In "Freddie", Effy arrives in Freddie's garden and asks to be allowed into his shed. Inside, the two share a spliff, but are quickly joined by the arrival of Cook and JJ. When Cook invites Effy to leave to have sex with him, she sarcastically rebuffs him, causing him to angrily insist that she leave, which she does. Afterward, as Freddie returns a bracelet to her, he suggests that they would be "good together." Effy denies this by claiming she would break his heart, to which he counters "maybe I'll break yours." She then dismisses this, saying "nobody breaks my heart."Later in the episode, Freddie seeks out Effy at the lake, where she is escaping from her turbulent home situation. Having been encouraged by his father not to just 'skate around', he decides to be up-front and swims out to meet her. The two share a passionate kiss in the water, where Freddie tells her how he feels about her. Nevertheless, by the end of the episode Effy has returned to Cook, and she and Cook watch from her bedroom window as Freddie watches from below. In "Naomi", although there is apparent tension between Effy and Freddie the plotline goes undeveloped.
In the next episode, "JJ", Naomi and Effy share a brief moment where Naomi seems troubled by her own sexuality but Effy doesn't judge her. In turn Naomi cleverly points out that Effy is in love with Freddie, much to Effy's discomfort. Cook also confesses that she is in love with Freddie while he is high on JJ's latest medication; Freddie is shocked by this revelation, especially as he has just started a sexual relationship with Katie Fitch (perhaps doubting by now if it is worth playing Effy's game).
In her central episode, she is prepared to break up with Cook — which she does without informing him — and confront Freddie with her feelings, but is discouraged when she discovers Freddie's new relationship with Katie.
Later in the episode after the gang, sans Cook, goes camping, Effy and the others take some "shrooms" and get high. Katie witnesses Freddie and Effy sharing a cigarette and gets jealous. Effy later holds Freddie's hand as he lies with Katie and she with Pandora. Later, while high, she decides take a walk into the woods where she is attacked by a jealous and insecure Katie, who pins her down and spits on her before attempting to choke her, telling her that Effy will never be better than her and that she needs to leave Freddie alone. Effy, still under the influence of the shrooms begins to freaks out, picking up a rock and strikes Katie in self defense, knocking her out.
Afterwords, Effy wanders back to the campsite and sits by a sleeping Freddie and begins stroking his face. She startles him and he awakens, grabbing her wrist. After a few tense moments, they kiss and have sex for the first time. However, the next morning when the gang notices that Katie is missing, Effy becomes extremely anxious, and lets the gang think that she must have gone home early. Eventually, Katie is found and taken to hospital, where Freddie — among others — learns that Effy hit Katie (but not the reasons why), thus turning against Effy for thinking she attacked Katie without merit. Cook then picks her up and they drive around the country for weeks from one town to another. She eventually finds out that Cook is searching for his father. When they reunite Effy grows worried for Cook when she sees how his father manipulates him, prompting her to call Freddie for help. During their phone conversation she tells him that she loves him shortly before hanging up. Freddie, meanwhile, has taken to chain-smoking weed to deal with his depression, and JJ has to goad him to go after her.
When Freddie and JJ arrive, they decide that the fate of the boys' relationships with Effy should be decided by who wins the small town's race. JJ, who wins the race, takes charge and demands that they solve their problems once and for all, forcing both boys to admit that they each love Effy and telling her that she must choose between them.
Although Effy doesn't say anything, her "look says it all" when her gaze lingers over Freddie, prompting Cook to leave in a fury. When Freddie and Effy are alone, he berates her for having torn their friendship apart, saying it is entirely her fault for starting the whole thing with the list. Although Effy's only answer- 'I know'- is unsatisfactory to Freddie, he quickly forgives her; they kiss and have sex, later leaving town with Cook and JJ in Cook's father boat.
Effy does not appear until the conclusion of "Thomas". Except for Pandora, at whose house she is staying, the rest of the group believe she has simply left for the year; Freddie suspects that she dumped him to compensate for what she did to Cook in the previous season finale.In "Emily", Effy returns to college after spending the summer abroad in Italy. She sits next to Freddie and steals one of his chips. They talk for a while and Effy reveals that it's him she was thinking about all summer. She then hugs Cook in a friendly manner while Freddie watches. Emily then asks Freddie if he can trust her.
Later at a party Effy is dancing with Freddie and kisses him. Cook sees this and lashes out at a fellow party-goer and headbutts JJ in a jealous rage. Effy and Freddie see him fighting and leave.
In "Cook", Effy and Freddie kiss and are overseen by Cook, who tells Freddie to fuck off when he is expelled.
Cook visits his mother’s art exhibit. One of her exhibits lists every one of her lovers, and to his horror he sees Freddie's name. When confronted by Cook Freddie explains that she gave him a blow job on his fifteenth birthday.
Effy comes to see Cook in prison and tells him she loves Freddie. He asks her "how is the love?" Effy replies that it messes with your head, but she's giving it a go. During "Katie" she is seen at various gatherings with Freddie; while she is taking somewhat large ammounts of drugs and liquor, the affection they are showering one another with is obviously sincere.
In "Freddie", Freddie and Effy are living a hedonistic lifestyle in the Stonem house with Anthea gone. Freddie's education suffers and when he tells Effy this, they argue. While he feels they need to rein in their wild behavior eventually, Freddie is clearly enjoying the ride. Freddie meets a counsellor about his unfinished coursework, who offers no help; nonetheless, he manages to complete it even while keeping Effy his top priority. Freddie returns to see Effy sticking newspaper cuttings about death onto the wall, and Effy talks about her "end." This leads him to become concerned about Effy’s mental state. He talks to his grandfather, Norman, and becomes determined not to make the mistakes with Effy he thinks his father made with his mother, who committed suicide.
He then lovingly cares for her, bringing her out of her stupor, and bathes her. They then go to a park, where they run around chasing each other and end up lying on the grass. She then reveals her deep feelings for him saying, "from the moment I saw you, I knew you'd be the closest I'd get to being close. And I didn't know what to do with that feeling . . . happiness." Soon after she is seen getting frenzied, and imagines that a crowd of people are approaching them when in fact no one is there. Freddie, however, plays along, and pretends to scare them off, with Effy laughing along. She then gets anxious again and insists she goes home.
As they return home in a rickshaw they borrowed they see Anthea speaking to a policeman outside the house, having returned home to see the terrible state it was in and Effy's morbid collection of pictures, so Freddie takes her away. They are caught in the middle of a hectic carnival- one full of demonic images of the sort Effy has been imagining. Terrified, Effy runs off and Freddie chases after her. Overwhelmed, she covers her ears. Katie, who is performing in the festival on a float, sees her and brings her up, hugging and comforting her. In the meantime Freddie runs into Cook, dresses as a devil, who helps him find her. When they reunite Cook then leaves and Freddie holds and comforts her.
Unsure of where else to go Freddie takes Effy, with Katie in tow, to his grandfather's residence, explaining the situation to him. Katie interrupts them, saying Effy won't come out of the bathroom. Freddie realizes what is happening and runs down the hall to the bathroom, finding it locked. He then breaks it down to find Effy lying in blood, having attempted suicide by slitting her wrists. He calls for help and she is taken to the hospital.
At the hospital Freddie is joined in the waiting room by his sister Karen, who helps him fold an origami swan, which he places on Effy's bedside table.
After visting with Effy- who tells him to go away- he talks outside with Anthea, both having a smoke. Anthea says Effy will get through it with their help, but Freddie runs off. He goes to her house and takes all of her photos, including one of him, and burns them in the backyard. Cook joins him and holds him as he sobs.
During the "Lost Weeks" Episode, Effy wakes up from a recurring nightmare in which she sees a black figure chasing her in a forest and a younger version of herself who tells her to 'cut open the swan'. As she looks around, she sees a new origami swan from Freddie, and unfolds it to find the words 'love you forever'.In "Effy", Effy returns home after her suicide attempt, with her room completely clean, and she and her mother have an awkward conversation. Effy then draws a time table on her white board, and Freddie's name is seen.
She unpacks and then goes to visit him, and he is very excited to see her. Inside Freddie's room, she and Freddie talk. He asks her why he wasn't allowed to see her, to which she replied that her docotr, John Foster had forbidden anyone from seeing her, as it was part of her treatment. When Freddie asks what Foster did that was so special, Effy replies that he took away all her bad memories and made them good. Freddie is angry, finding out that Effy had bad memories of him.
Effy consoles him, stating that now that all the bad memories were taken away, all she feels for Freddie is love. They then kiss and presumably have sex.
She then goes home and takes her pills, and the viewers see Freddie's name disappear from her white board.
Later, when at a restaurant with the gang, Effy says she feels like she is in a different place and shouldn't hang out with any of them anymore, not even Freddie. She then says goodbye and returns home.Freddie later confronts her and they get into an argument. He tries to kiss her but she pushes him away.Effy tells him that she went mad when she was with him and that love is not supposed to do that, but Freddie counters, saying that's exactly what love is supposed to do. He then leaves, and Effy runs her fingers through her hair.
The next morning she is seen sitting on a park bench, staring dreamily into the sky. Cook joins her. As they are talking, Cook mentions that Freddie called him about her, referring to her as "Eff." Effy looks confused, asking who "Eff" is. It turns out that Foster has been making Effy forget everyone she ever loved, including Cook and Freddie. Cook plays along, introducing himself as James, his first name. They spend the day together, but later in the evening Effy has an inadvertent flashback to her brother Tony being run over, and believes that they are at the scene of the accident. She then runs away from Cook, who chases her to a freeway. Effy runs into the middle of traffic, screaming "I'm not scared! I want to be scared!" Cook saves her from an approaching van and they fall to the side of the road and share a passionate kiss. She then asks him to take her to Freddie before passing out.
Cook takes her to Freddie's house, and when she wakes up, she apologizes to Freddie and they reconcile. She tells him the voices have started up again, but Freddie says they'll handle it together.
When she returns to the rehabilitation center where she was treated Foster enters the Effy's room. She freaks out and tells Freddie she doesn't want Foster to be her shrink anymore. Freddie tell him to leave her alone, which he does, and then the two hold hands until she falls asleep, as she whispers "I love you" over and over again, making him cry. He hugs Anthea- who like him, strongly mistrusts Foster- and leaves.
Foster later calls Freddie, asking him to meet at Foster's house to talk about Effy. When he arrives Foster attacks him with a baseball bat, cornering Freddie at the top of a staircase as he tries to break through a locked door and escape. Blood is then seen splattered on the glass, and we hear Freddie's screams, suggesting he was beaten to death.
Freddie goes missing and is assumed to have run away. Effy is tortured because he "left" without saying goodbye. While in Freddie's shed Cook gives her Freddie's notebook, with page after page saying "I love her" on each line. On each page the words grow longer, presumably as his love for her became stronger. She cries, as this confirms his undying love for her.
Upon Karen's prompting Cook goes searching for Freddie. He sees John Foster lurking outside the shed as the gang celebrates inside. He follows him and breaks into his home. In the basement he sees Freddie's clothes covered in blood. Foster catches Cook and they have a confrontation. In a rage Cook head-butts him, this being the last moment of the series, with their fates remaining unknown but is later revealed in Series 7 that Cook killed John Foster.