When Dad sells Candace's favorite childhood doll to Doofenshmirtz at a yard sale, Phineas and Ferb become Film Noir detectives to help her find it. Meanwhile, Dr. Doofenshmirtz gives the doll to Vanessa (who desperately wanted it when she was seven) as a way of showing her that he loves her. After that, Doofenshmirtz decides to fire up an inator he bought at another yard sale, but he needs to find a switch in order to turn it on.
Tropes:
- The Alleged Car: During the song, when Doof gives Vanessa her driving test, the car she drives falls apart when they reach Charlene's house.
- Amazingly Embarrassing Parents: Vanessa's song highlights a number of her father's antics, including clapping wildly at a recital and interfering with a baseball player catching a foul ball.
- Artifact of Attraction: When the Mary McGuffin doll was released, it caused girls to fight with each other over having it; Ferb notes that this was the reason the doll was discontinued in the first place.
- Astonishingly Appropriate Interruption: Phineas says he'll get Candace her doll back before she can say...Phineas: Hey, where's Perry?
- Bait-and-Switch: Doof uses a poor choice of words when saying he has a surprise for Vanessa. He says he has "the key to", and Vanessa assumes he's talking about a car, but instead, he says, "No, your happiness!"
- Bittersweet Ending: Candace doesn't get her doll back (though she seems to have accepted this), with Vanessa having taken possession of it, but the good news is that Vanessa's on better terms with her father.
- Borrowed Catchphrase: When Candace sees her brothers are playing film noir private dicks, she declares, "I know what you're gonna do today!"
- Comically Missing the Point: When Lawrence tells Candace he sold her doll and offers her the dollar he got for it, she gets so upset that she screams very loudly at him. Being unable to understand why his daughter is so mad at him, Lawrence offers her two dollars instead.
- Continuity Nod: Doofenshmirtz says that "life was much simpler when I worked as a lawn gnome".
- Determinator: Vanessa asked Doofenshmirtz for a Mary McGuffin doll when she was seven. He spent a decade scouring the internet and garage sales to find one.
- Film Noir: Phineas and Ferb's segment of the episode parodies this.
- Garage Sale: The Flynn-Fletchers host a yard sale at the beginning of the episode.
- Gift for an Outgrown Interest: Doofenschmirtz has been searching for a Mary McGuffin doll for over a decade to give to Vanessa. Although she's long outgrown it, she's touched by his dedication, and concludes he's not such a bad dad after all.
- Graceful Loser: Perry is this upon being berated by Doofenshmirtz for fighting him over buying machinery that only opens and closes a lobster cage, which isn't considered evil. He even gives Doof a thumbs-up for pointing that out.
- Gratuitous German: Doof's Drusselstinian heritage comes out when he sees a matching switch but he thinks the words are printed upside-down, and he wonders what kind of dummkopf would make that kind of switch. Of course, he was holding the switch upside-down.
- Impossibly-Compact Folding: Phineas and Ferb's black-and-white interrogation booth is able to shrink and fold to a much smaller size.
- Leaning on the Fourth Wall: When Lawrence overhears Phineas narrating:Lawrence: Who is he talking to?
Candace: Ugh, don't get me started. - Left the Background Music On: The smooth jazz heard in the background while Phineas and Ferb are dressed in black and white is being played by Ferb on a saxophone.
- Literal Metaphor:
- When Candace asks Phineas and Ferb to track down her Mary McGuffin doll, Phineas says, "Piece of cake". Ferb then hands Phineas an actual piece of chocolate cake.
- Phineas and Ferb are interviewing the owner of the Lab Coat emporium. When he feigns ignorance, Phineas says, "Alright Ferb... lean on him". Ferb then proceeds to lean on his shoulder, and the owner exclaims, "Alright, alright, I'll talk!".
- MacGuffin: The Mary McGuffin doll is named after this trope, as it's something both Candace and Vanessa want.
- Memento MacGuffin: Doofenshmirtz had been looking for the Mary McGuffin doll for Vanessa since she was seven years old, which gives the doll a lot of sentimental value to her as it proves how much he cares for her. She and Candace fight over the doll until it ends up in the hands of a little girl. Candace decides she's too old for dolls anyway while Vanessa ponders whether she should give up the doll that means so much to her. She doesn't, and takes the doll away from the girl.
- Metaphorgotten: "The sun beat down on the city like a hammer. A relentless, hot, beating hammer hammering down like a big metaphor that was... hot.. for some reason."
- Painting the Medium: In a literal sense, as Phineas and Ferb are depicted in black and white, as Phineas reveals they put some black and white makeup on themselves to get into character. They also somehow put black and white makeup on a man being interrogated.
- Parental Love Song: "Not So Bad A Dad", sung from Vanessa's perspective as an appreciation of how Doofenshmirtz cares about her enough to track down a doll she wanted years ago.
- Perp Sweating: Phineas uses this on an unnamed man and on Charlene.
- Rearrange the Song: The Evil Jingle is also done in the style of the CSI: Miami theme.
- Subverted Catchphrase: When Charlene asks Phineas if he's a little young to be a detective, Phineas, still in character, says, "If it's all the same to you, ma'am, we'll ask the questions here."
- Shout-Out: While trying to find which Charitable Charities location has Candace's Mary McGuffin doll, Phineas and Ferb try out other cop personas, referencing Starsky & Hutch, Miami Vice, and CSI: Miami.Charitable Charities Clerk: Aren't you a little young to know about all these old detective shows?Phineas: Yes. Yes we... puts on sunglasses ...are.
- So Proud of You: Doofenshmirtz, upon being told that Vanessa took the doll from the little girl.Doofenshmirtz: So, you just took it from the little girl and left her there, crying? Wow, that is evil. Honey, I am so proud of you!
- Villain Has a Point: Near the end, Perry engages into a fight with Doofenshmirtz, but Doof (in a rare moment of common sense) points out that all he did was buy machinery that opens and closes a lobster cage (which he briefly trapped Perry in), and that it would be pointless to fight over it, so he happily curses Perry for attacking him over such a silly issue. Knowing that Doof makes a good point, Perry concedes defeat and leaves.Doofenshmirtz: Wait, hold on one second here, just a second. It occurs to me that all this [switch] does is open and close a lobster cage; you know, it's not even evil, much less illegal. Besides, I've run out of clever fighting puns so, curse you, Perry the Platypus.
