The story takes place in a mansion where an engagement party is being held. The guests are playing a game called "Sardines," which is similar to hide-and-seek. The first person hides, and then the other partygoers look for them one by one. When someone finds the hider, they hide together with them. Then the third, fourth, fifth, sixth... more and more people join, packed together like sardines. A crowded game of Sardines would have sparked endless laughter and joy in our childhoods, but, well, they are children who grew up in a mansion.
The scene opens with Rebecca entering a suite in the mansion. Rebecca is the daughter of the mansion's owner. This room clearly holds many memories for her. She walks in, goes to the bathroom, looks around, then picks up a red bar of soap and inhales its scent deeply and emotionally. Returning to the room, she checks under the bed and behind the curtains, then walks straight to the wardrobe, opens the door—Bingo! The man inside says to her: "Oh! You were quick." Rebecca says, "Yes, I know the house." The man says something superficially relevant but loaded with implication: "Yes, you have an advantage. An unfair advantage over others." Rebecca says, "Yes," and then she also squeezes into the wardrobe. Being in a dark wardrobe with a man makes Rebecca a little nervous, but this man has a baby face and a chubby, friendly appearance. He volunteers, "I'm Ian. You're Rachel, right?" Rebecca corrects him. Then Ian tells her, "Jeremy and I are colleagues." Jeremy is Rebecca's fiancé; today's party is for their engagement.
They chat for only a few moments before a young man enters. His name is Lee, and he's Rachel's boyfriend. But Lee is clearly not invested in the game; he gives the room a cursory glance and leaves, closing the door. Ian continues chatting with Rebecca: "How does it feel to be engaged, Rachel?" Rebecca corrects him again. They talk about the wedding date; Rebecca says it's November 9th. Ian immediately says, "OMG, 9/11!" Rebecca says she never made the connection, but is clearly displeased. At this point, Ian is definitely doing it on purpose. Then, he says strangely again, "My baptismal initials were R.I.P., can you believe it?"
Before Rebecca can respond, the wardrobe door opens again. Rebecca's brother, Carl, enters and squeezes in. Before entering, he ambiguously strokes his sister Rebecca's hand and says, "You could never find me when we played hide and seek as children, could you?" His tone carries a peculiar mix of accusation and melancholy. After her brother enters, Rebecca takes on a girlish expression and asks coyly, "Daddy will play too, won't he?" Her brother says yes. Next, Carl's friend Stuart makes his entrance, holding a wine bottle in one hand and a glass in the other. He enters the wardrobe noisily and mentions someone named John downstairs who smells bad. The siblings both say, "Oh, 'Stinky John'," but Carl adds, "He didn't smell when we were at school with him." Rebecca agrees, "Yeah, don't know when he stopped washing."
After Stuart, Rachel enters. Ian pretends to be casual, greeting her with, "Oh, so you're Rachel. Jeremy talks about you all the time." Ian's malice is now evident, as Rachel is Jeremy's ex-girlfriend. But with his baby face and cheerful grin, he looks utterly innocent and harmless. Rachel can't stand being in the wardrobe and comes out for air. Stuart and Ian also come out. Stuart goes to the toilet, opens the door, and finds the mansion's former housekeeper sitting on the toilet. The old woman is dressed like a bird and speaks in a chirpy voice. Stuart closes the frosted glass toilet door, but Carl stares at the blurry figure behind the glass for a few seconds, looking distracted.
Soon, everyone returns to hide in the wardrobe. The housekeeper suddenly says, "I haven't been in this room for years. Your father locked it after... that happened…" But Rebecca quickly cuts her off: "Let's not talk about that." In this awkward moment, a married couple attending the party enters the room, and everyone holds their breath.
Mark and Elizabeth are the peripheral characters in this story; they attend the mansion's parties for social advantage. Seeing the room empty, they start getting passionate. The people in the wardrobe, feeling awkward, make noise to interrupt them. The couple then also joins the sardines in the wardrobe. Just then, Lee, Rachel's boyfriend, passes by the room with his glass and joins in. But the wardrobe is too crowded, so Lee and Stuart hide under the bed together, sharing champagne. Ian also takes the opportunity to get out. Once out, Ian behaves very strangely, looking around intently, then quickly runs into the bathroom.
The room seems bathed in a tranquil, serene glow of nostalgia. But there are six people in the wardrobe, two under the bed, and one in the bathroom. The calm before the storm lasts two seconds. Then the writer deliberately uses some crude humor from Stuart to break the tension for the audience. Stuart, from under the bed, says loudly, making Carl jealous: "Lee, don't stop, that's so good, oh my god your hands are so big, don't stop."
Finally, "Stinky John" makes his entrance. John genuinely looks like he hasn't bathed in years; you can almost smell him through the screen. So, the people in the wardrobe hold the door shut against him. Stuart and Lee under the bed also don't welcome him. He has no choice but to hide behind the curtains.
Before John is properly hidden, Jeremy enters. Jeremy is looking for his fiancée, Rebecca. He needs to go to the station to pick someone up. But when saying goodbye to Rebecca, he blurts out, "Bye, darling Rachel." Flustered, he desperately tries to explain. At that moment, his future father-in-law, Andrew, enters.
The big boss has arrived. Seeing that everyone isn't strictly following the rules of hiding in one spot, he authoritatively stuffs the five "sardines" outside—including himself—into the wardrobe and personally closes the wardrobe door. Now, the wardrobe is packed with 11 people.
Once the old man is inside, he starts singing the "Sardines Song": "One little sardine, saw a submarine..." He only gets two lines in before his son Carl sharply rebukes him: "How dare you sing that song!" But Father Andrew is tougher: "It's my own house, I'll do what I like." The camera pans, showing unusual expressions on Carl and Stinky John's faces. After a moment of silence, the housekeeper chimes in: "Does everyone remember the Boy Scout rally back then? The house was full of Boy Scouts, so lively, having such fun. And then one boy ruined the fun. What was his name? The police came too, made a huge mess." John prompts the boy's name. The housekeeper says, "Yes, yes, his name was little Pip. Where did he go later?" The old man says, "Moved away. To Spain or Somerset." The housekeeper then says to the old man, "Probably for the best, moving away. To accuse you of such a terrible crime!" Carl says from the corner, "He didn't move. The old man paid them to leave." The old man protests: "I was just toturing that boy about washing. Basic hygiene." Carl retorts pointedly: "Pity not all of us were that lucky, eh, John?" John, squeezed at the very back of the wardrobe, says painfully, "I can smell the soap."
With two minutes left in the episode, the 11 people are crammed together in the wardrobe. Rachel is already impatient. Stuart says, "I think that's everyone. No one else is going to come looking for us now." Lee says, "No, there's still an Ian. He's not in here." Jeremy says, "Right, that's who I was just going to say I need to pick up from the station." Then Mark says that Ian is already here, he's in the bathroom, some boring guy with glasses. Jeremy says, "That's not Ian." Then, the scene cuts to outside the wardrobe. Someone is locking the wardrobe from the outside.
It's the man who called himself "Ian"—Pip. He leans against the wardrobe and sings affectionately: "One little sardine, saw a submarine. He was very afraid, peeped through a hole. Come on, come on, the mother sardine called him, the submarine is just a tin of men..." As he sings, he pours gasoline on the floor and flicks open a lighter.
Several stories in Inside No. 9 cannot be fully understood in one viewing, especially this first one. For the first twenty-seven minutes, every line of dialogue lays a subtle trail of clues. Only on a second viewing can one mostly understand: Oh, so many years ago, there was a Boy Scout party. The old man, Andrew, is a pedophile. He sexually assaulted boys in the bathroom using soap. That's when John stopped bathing. But one boy named Pip reported the old man. Unfortunately, the police were bought off by the old man. The first person to hide in the wardrobe, "Ian"—his real name is Pip—has now returned for revenge. His first words to Rebecca, "You have an advantage," and later Carl's words to Rebecca, "You could never find me," both contain envy of Rebecca's gender and condemnation of her standing by.
Rebecca and Carl have another sister, but this sister didn't come to her sister's engagement party. Perhaps the sister is protecting her own son. Or perhaps, when Andrew was assaulting the Boy Scouts, all three siblings witnessed everything from inside a wardrobe. In the episode, Carl looks very distracted staring at the frosted glass bathroom door; he must have seen his father's crimes and was likely also abused by him. But Rebecca's perception of her father is different; she might see authority in his actions, so she worships and depends on him. When Old Man Andrew committed his crimes, he must have sung the "Sardines Song." Thus, when Pip carries out his final revenge, he must also sing the "Sardines Song."
The baby-faced avenger Pip said one thing: "This place is like a time machine." The wardrobe in the room faces the bathroom. The evil that happened in the bathroom all those years ago is now reflected, mirror-image style, into the present. Childhood wounds never truly healed. The Sardines game is the original sin from that long-ago Boy Scout party. The Boy Scout Pip is the eternal wound of the Sardines game. Inside No. 9 is a time machine where some people stopped growing up and others aged instantly. But now, none of that matters. Eleven people, all guilty to varying degrees, are locked back into the wardrobe. The sardines enter the same can, forced to relive the past sin together and be thrown back to the starting point. They are the already contaminated sardines, about to be rebaptized as sardine babies.
Perhaps this is also why this gloomy revenge story maintains a black comedy effect throughout. The chief villain, Old Man Andrew, merely seems domineering, not lecherous—a point that critics who dislike dark themes find objectionable. They say most fans of Inside No. 9 have psychological issues. Whether that's a problem or not, I don't care. What I want to emphasize is the "9".