Elementary My Dear Stacy

While in London, Candace and Stacy emulate Sherlock Holmes while trying to bust Phineas and Ferb. Meanwhile, Perry must team up with British agent Double-0 0 in order to stop Dr. Doofenshmirtz from moving Big Ben to the Tri-State Area.

Episode Summary
Still on vacation in London, the Flynn-Fletcher family is joined by Stacy Hirano. She and Candace stay up all night reading stories, even though they originally mocked reading as something people did "before they invented fun." The next morning, the adults take along with Candace and Stacy to see the, a giant Ferris wheel.

Once the family leaves, Perry the Platypus opens the face to the grandfather clock and zips down a chute into a comfortable arm chair, in what appears to be his lair while he is in London. After Agent P's last mission in London, the Agency ran into some trouble with the British Spy Union. So, he is assigned a partner for today's mission, Agent Double-0 0.

Grandpa Fletcher and Lawrence drop the rest of the family off at the London Eye and head off to the International Haggis Festival. Once there, Linda and Grandma Fletcher head off to explore downtown London, leaving the kids to wait in line for the ride by themselves. They further split into two groups, with Phineas and Ferb together and Candace and Stacy together.

Candace figures that her brothers have some scheme planned even though they are in London. She believes that she might finally be able to bust them if she uses Holmes' method of deduction. Even though Stacy would rather go shopping, she agrees to help her friend and takes on the role of.

After trying to squeeze into Perry's hover car, the two spies take Agent Double-0 0's car. The British agent explains all the gadgets that his car is equipped with, and Perry inadvertently hits the ejector seat button, propelling Agent Double-0 0 out of the car. Once back inside, he asks Perry if he thought it was funny.

Candace and Stacy are walking through downtown London and Candace has bought a hat and cape just like Sherlock Holmes usually wears, while Stacy has a  like that of Dr. Watson. Stacy gets distracted window shopping in all the stores. Candace sees her brothers head into an auto supply store and starts making several outrageous leaps in logic as to what they could be doing.

The two agents arrive at Dr. Heinz Doofenshmirtz's London lair underneath. After making fun of Agent Double-0 0's name, Doofenshmirtz reveals his plan to launch Big Ben into orbit and land it outside Doofenshmirtz Evil Incorporated's main building so that he doesn't have to look at his tiny watch. Agent Double-0 0 ridicules Doofenshmirtz's plan, saying that he could just buy a bigger watch or a wall clock. The scientist feels launching the famous landmark into space is easier than going into a store and picking one of those out.

After talking to the auto supply store manager, Candace and Stacy follow the boys' trail out back to find that they've picked up the free tires the store was offering. After chasing them around town and pulling Stacy out of several stores, Candace is close to figuring it out.

The boys drop a notebook while getting into a cab, and the girls pick it up. Half the page is missing, but it reads, "To Big Race 1600 Water S." Candace deduces that they must be planning a big race at 1600 Water St. She calls her mom, but arrives at the address only to find the building is abandoned and Phineas and Ferb are nowhere to be found. She then remembers an old Holmes trick to use pencil lead to reveal impressions left on a piece of paper. Candace tries this and it reveals the note to read, "To Do Today: Big Ben Race To Thames 1600 for Water Slide Fun."



Agent Double-0 0 is using his watch laser to open his and Agent P's traps. Since it is taking so long, Perry figures out that he can throw a nearby brick on the remote control and release the trap. Once free, Agent Double-0 0 climbs up through the inner workings of Big Ben to go undetected and surprise Doofenshmirtz. Agent P decides to take the elevator instead.

The girls arrive at Big Ben and find that Candace was right. They were making a water slide at Big Ben. It loops around the clock tower and the finish fires them off into the London Eye. As Phineas and Candace are discussing her method of deduction, the lift comes down and brings her up to the top and she is launched into the slide while she is on the phone to Linda. Stacy decides to voluntarily ride the slide, and Phineas hops on as the last customer of the day. They all land safely in the Ferris wheel.

Across the, Big Ben is starting to soar into the sky with the slide still wrapped around it. Doofenshmirtz is at the top of the tower basking in the glow of his success when Perry leaps up and knocks the remote for the rocket out of his hand and knocks the evil genius down the slide. All the stress on the structure breaks the slide apart and it falls into the river. Perry pushes the button and the clock tower floats back into place just in time for Linda not to see any of it.

Songs
Elementary

Ferb's Line

 * "I'll never understand fashion."

Whatcha doin'?

 * None.

Perry's entrance to his lair
Goes down the Fletchers' grandfather clock to land in a lair beneath the Fletchers' house. It is furnished in a very traditional British style. He is soon joined by Agent Double-0 0.

End Credits
Double-0 0 is still trying to reach the ladder from the pendulum. He then manages to get out through a door under the hands of the Big Ben and looks at his clock to find out how much time he has been in there, but complains about his watch being too small.

Background Information

 * It premiered on Disney XD on February 28, 2009 and on Disney Channel US on May 15, 2009.
 * A sneak peek was shown on Disney Channel.

Continuity

 * Even though it seems to take place during the same vacation to England as "A Hard Day's Knight", it is unclear how Stacy arrived in England, as she was not with the family in that episode.
 * Once again Stacy has a hard time focusing on busting Phineas and Ferb. In "Put That Putter Away", one of the instructions a sick-in-bed Candace gave to her was, "Focus."
 * The first one to be shown going up the water slide is the boy in the commercial of Bust 'Em. (Leave the Busting to Us!, Leave the Busting to Us! (song) )
 * Candace and Stacy appears wearing the Sherlock Holmes and Watson Outfit. Though might be the first time, Phineas and Ferb used it in the Episode Toy to the World

Allusions

 * When Major Monogram gives Agent P his mission, he mentions about his last mission in London, which took place in A Hard Day's Knight

Sherlock Holmes

 * Candace imitates the great detective quite a bit during this episode, including wearing the clothing most commonly associated with Sherlock Holmes: the deerstalker hat and cape featured in Sydney Paget's illustrations for Strand Magazine.
 * Candace designates Stacy as Watson, Sherlock Holmes' most trusted companion. which has helped him in all of his most fascinating cases.

James Bond

 * Agent Double-0 0 is a very direct parody of James Bond.
 * Inspector Initials is a parody of Bond's boss, M, as the character is currently being portrayed by Dame Judi Dench.
 * Double-0 0's laser watch is similar to many gadgets that Bond has been equipped with over the years, most directly the laser watch featured in 1995's Goldeneye.

"Elementary, my dear Watson"

 * The episode title comes from the famous phrase which was not actually said by Sherlock Holmes in any of the Sir Arthur Conan Doyle works. The line "Elementary, my dear Watson" was either first said in the 1929 movie The Return of Sherlock Holmes or in the 1899 stage production Sherlock Holmes.

Cast

 * Vincent Martella as Phineas Flynn
 * Thomas Sangster as Ferb Fletcher
 * Ashley Tisdale as Candace Flynn
 * Kelly Hu as Stacy Hirano
 * Alyson Stoner as Isabella Garcia-Shapiro
 * Caroline Rhea as Linda Flynn
 * Richard O'Brien as Lawrence Fletcher
 * Dee Bradley Baker as Perry the Platypus
 * Jeff "Swampy" Marsh as Major Monogram
 * Dan Povenmire as Dr. Doofenshmirtz
 * Malcolm McDowell as Reginald Fletcher
 * Jane Carr as Winnifred Fletcher