The Cuckoo episode 1 introduces us to Jessica and Nick, who have recently moved into a beautiful, remote property in the countryside with their adopted daughter. However, their idyllic life is soon disrupted by financial issues, and they decide to take in a lodger.
It's a difficult decision, and the couple's 14-year-old daughter Alice is against the idea, not wanting anyone else in their space. But when Sian arrives, the family think they've hit the jackpot, as she seems like a charming new resident to help them balance the books.
However, it doesn't take long for things to go awry and Jessica starts having concerns about Sian's behaviour, which the first episode begins to explore.
Here's what went down in episode 1...
The lodger
This episode opens by showing viewers inside the countryside home, where Jessica is giving a potential lodger a tour of the place. However, it is unsuccessful when the lodger admits she has a few cats, and the advert said no pets. Unable to budge on this arrangement, the lodger leaves.
Jessica is frustrated and there's tensions between her and her husband Nick, who seems a bit more relaxed but she won't budge on her terms. She goes upstairs and speaks to their daughter Alice, who is drawing, and calls her art "a bit creepy" before using a nickname she dislikes. Alice tells her not to call her that, and it's immediately clear their relationship is strained.
They argue, and Jessica tells Alice "they're getting a little tired of the act" before storming out of her room. The house is still in need of some work, and when Jessica tries to get a drink of water it's dirty, and she complains about the plumbing. Nick attempts to console his wife, who is clearly stressed and she brushes him off, saying everything's getting to her.
Nick and Alice head out to get groceries, and Jessica is starting to lose hope about ever finding a lodger, but a woman named Sian arrives saying she's come about the room and is interested in renting it. Sian compliments the home and the colour choices.
As she's showing Sian around the place, she explains Alice also enjoys art and the two seem to be getting along well, with Sian also complimenting the view from her room. But the conversation is interrupted by their plumber's wife, demanding payment for work, leaving Jessica embarrassed that Sian had to witness this. Sian is understanding and offers to cover the bill with her deposit, which Jessica accepts.
Nick and Alice return home and are introduced to their new lodger, with Jessica agreeing to take her on. However, it's an awkward situation with Alice feeling uncomfortable about her presence, and Nick not particularly happy about taking all that money from Sian, and he's also annoyed that she didn't discuss the decision to take Sian in with him, so there's some disgreements between the two.
Sian makes breakfast for everyone the next morning and Jessica is shocked, saying she didn't have to, but she insists it's fine and it's a thank you for letting her stay with them. Alice finds the situation uncomfortable and says she's not hungry, and that someone needs to take her to school, and Jessica apologises to Sian before running after Alice.
Later that day, the plumber's wife approaches Jessica and apologises for her behaviour, saying they'll fix the shower for free. Jessica is baffled by the sudden kindness and Sian arrives, saying she'd had a word and claimed that Jessica was sick. Jessica laughs it off but worries that the lie will be exposed eventually.
Meanwhile, Nick does some research into Sian and realises she has no social media, which he finds strange. During a conversation in a local pub, Jessica admits to Sian that she struggles to bond with Alice and that Nick had an affair, so their family life is not perfect, and Sian defends her and says what Nick did was wrong. When asked about why she took the room, Sian says she's "figuring stuff out", and Jessica assumes it's a breakup or similar.
Back at the house, Nick contacts one of Sian's references, as he's still a little suspicious of her. When one of the references picks up, he asks questions and learns that this Miss Calder is her aunt, and that's how she knows her.
Jessica and Sian come home drunk, interrupting a conversation between Nick and Alice. Nick takes Jessica upstairs, attempting to sober her up, and shoots a disapproving look at Sian. In their room, they argue, and Nick says that it's suspicious that Sian provided her aunt as a reference. Jessica doesn't respond and kisses him instead, and they fall back onto the bed together.
Elsewhere, Sian chats to Alice saying she wanted to check in. Alice admits she's "literally a stranger" and she claims she wants to change that, before the two go on to have a discussion about art. Sian encourages Alice to keep at it, and to pursue her dreams.
In bed, Nick tells Jessica that he knows his affair was a terrible mistake and a "betrayal of everything that matters to him". Jessica says she forgives him, and the two admit they missed having that connection.
On the way to school, Alice tells Jessica that she thinks Sian is "cool", and she agrees. Back at home, Nick makes a desperate phone call to a colleague where he asks for a loan, while Sian eavesdrops. She spots him taking down a framed photograph with a hidden safe behind it, where he takes out valuable jewellery. With no other option, and with loans he's struggling to repay, Nick pawns the jewellery for cash.
While Sian is unpacking groceries in the kitchen, Nick comes in and says that she needs to leave, handing over £3,000 in cash, which was the deposit Sian paid to Jessica. Sian makes a snide comment saying she hopes he didn't have to sell something to get that money, and says she signed a tenancy agreement that early eviction would be in breach of.
Sian doubles down and accuses Nick of having feelings for her, alluding to the fact she knows about his affair, and says "you think you can take whatever you want, don't you?"
Jessica and Alice return home, as a jar smashes in the kitchen. They find Sian cleaning up with a flustered Nick nearby, which leads Jessica and Nick to discuss the incident where she admits her fear of Nick cheating again.
The episode concludes with Sian leaving Miss Calder an unsettling voice message about her plan for Alice, revealing she believes that Alice is her daughter, saying "I'm going to get my baby back".
