Octonauts: Mary Poppins

Cast
Dashi Dog.........Mary Poppins

Plot
The film opens with Mary Poppins (Dashi Dog) perched in a cloud high above Disney Junior's London in spring 1910. The action descends to Earth where Bert (Shellington Sea Otter), a Cockney jack-of-all-trades is performing as a one-man band at a park entrance. The spectators watching him include: Ms. Persimmon ( Misty ), Miss Lark (Shelia Sea Otter) and Mrs. Corry (Gezibelle Sea Otter). He suddenly senses that his good friend is about to return. After the show, he speaks directly to the audience, introducing viewers first to Admiral Boom, who keeps his exterior rooftop "Ship Shape", by firing his cannon at 8:AM and 6:PM each day, and then to the well-to-do but troubled Banks family, headed by the cold and aloof George Banks (Andrew Bunny) and the loving but highly distracted suffragette Winifred Banks ( Tweak's Dad ).

The Bankses' latest nanny, Katie Nanna (Jessie), is quitting, exasperated after the Banks children, Jane (Coral Bunny Dotrice) and Michael (Nemo Bunny), have run off for the fourth time this week. Ellen, the maid (Petunia Penguin), pleads with her not to leave, but Mrs. Brill, the cook (May), wishes her good riddance. Mrs. Banks (Tweak Bunny) returns home, and engages all four women in a rousing rendition of "Sister Suffragette", before Katie Nanna (Dawn) stalks out. Mr. Banks (Andrew Bunny) returns home from his job at the Dawes Tomes Mousley Grubbs Fidelity Fiduciary Bank, and Mrs. Banks (Tweak Bunny) reveals the children are missing. A policeman (Arthur Treacher), arrives with the children, who ask their father to help repair their damaged kite, but he dismisses them and advertises for an authoritarian nanny-replacement. Jane and Michael (Coral and Nemo Bunny) draft their own advertisement asking for a fun, kind-hearted and caring person, but Mr. Banks  (Andrew Bunny) tears up the paper and throws it in the fireplace. Unnoticed, the remains of the note float up the dark chimney.

The next day, a queue of elderly and disagreeable looking candidates await at the door. However, a strong gust of wind blows the queue away and Mary Poppins (Dashi Dog) floats down, held aloft by her magical umbrella, to apply. Mr. Banks is stunned to see that this calmly defiant new nanny has responded to the children's ad despite the fact he destroyed it. Although Mary Poppins (Dashi Dog) recites the ad, she also tells George that she is firm and will also lay down ground rules with the children. As he puzzles, Mary Poppins (Dashi Dog)  employs herself and begins work, saying that she will stay for a trial period of one week, before deciding if she will take a permanent position. The children face surprises of their own: Mary (Dashi Dog) possesses a bottomless carpetbag, and makes contents of the children's nursery come to life and tidy themselves (by snapping her fingers).

The trio then meet Bert (Shellington Sea Otter), who is a close friend of Mary (Dashi Dog), in the park at work as a screever, where Mary (Dashi Dog) uses one of his chalk pavement drawings as a gateway to an outing in an animated countryside. While in the drawing, the children ride a merry-go-round while Mary and Bert enjoy a stroll through the countryside, during which Bert (Shellington Sea Otter) dances at an outdoor bistro with four penguin waiters. Mary and Bert (Dashi and Shellington) join the children on the merry-go-round, from which the horses break loose and take their riders on a trip through the countryside. As they pass by a fox hunt, Bert maneuvers to save an Irish-accented fox from the hounds. Finally the quartet finds themselves in a horse race, which Mary (Dashi Dog) wins. It is here that Mary first employs the nonsense word "Supercalifragilisticexpialidocious." The outing is interrupted by a rainstorm, which washes away the chalk drawing and returns the travellers, drenched, to the park pavement.

That evening, the children ask Mary how long she'll stay with them. With a somber expression, she replies, "I shall stay until the wind changes". The next day, they all visit Mary Poppins' (Dashi Dog) jovial Uncle Albert (Andrew Bunny's father), who floats up in the air whenever he laughs, and join him in a tea party in mid-air, telling various jokes to each other, though Mary finds it childish and ridiculous. They all get down only when one has to think of something sad, when Mary (Dashi Dog) firmly says it's time for them all to go home, which makes Uncle Albert (Andrew Bunny's father) very sad and tearful to hear this.

Mr. Banks (Andrew Bunny) grows increasingly irate with his children's stories of their adventures, but Mary (Dashi Dog) effortlessly inverts his attempted dismissal of her services into a plan to take his children with him to the Dawes Tomes Mousley Grubbs Fidelity Fiduciary Bank, where he is employed. On the way there, as they pass St Paul's Cathedral, the children see "The Bird Woman" (Tweak's grandmother), of whom Mary (Dashi Dog) sang to them the night before, and they want to feed the birds around her, but George will have none of it as he expresses his lack of interest in what Mary Poppins says and orders his children to "come along" and not mention her name for the rest of the day. Upon arriving at the bank, Mr. Dawes Jr (Pinto Penguin) and Mr. Dawes Sr (Peso's grandfather)—Mr. Banks' employers—aggressively try to persuade Michael (Nemo Bunny) to invest his tuppence in the bank to the point of actually snatching it out of his hand without waiting for his permission. When Michael protests, the other customers misunderstand and start a run on the bank that forces the bank to suspend business. The Bank Guard (Kwazii Cat) chases the children causing them to flee and wander into the slums of the East End of Disney Junior's London. Fortunately, they run into Bert (Andrew Bunny), now employed as a chimney sweep. He takes them safely home, explaining that their father does not hate them, but that he has problems of his own, and that unlike the children, has no one to turn to but himself.

At home, a departing Mrs. Banks employs Bert to clean the family's chimney and mind the children. Mary Poppins arrives back from her day off and warns of the dangers of this activity, but is too late as the children are both sucked up the chimney to the roof. Bert and Mary follow them and lead a tour of the rooftops of London that concludes with a joyful dance with Bert's chimney-sweep colleagues. A volley of fireworks from the Banks' eccentric neighbour, Admiral Boom (Reginald Owen), who mistakes them for Hottentots, orders Mr. Binnacle (Don Barclay) to set off the fireworks which sends the entire gathering back down a different chimney, which turns out to be the Banks' chimney. Mr. Banks arrives home, causing the chimney sweepers to depart outside the home, and out into the street, where they disappear from view within less than half a minute. Their departure concludes the festivities. Banks angrily inquires Mary Poppins what was the meaning of this, to which Mary replies that she never explains anything. Banks then receives a phone call from work ordering him to return immediately for disciplinary action. As Mr. Banks gathers his strength, Bert points out that while Mr. Banks does need to make a living, his offspring's childhood will come and go in a blink of an eye, and he needs to be there for them while he can. The Banks children approach their father to apologize, and Michael gives Mr. Banks his tuppence in the hope that it will make things all right. Banks gently accepts the offering.

A somber and thoughtful Mr. Banks walks alone through the night-time streets, for the first time noticing several of the buildings around him, including the Cathedral and steps on which the bird woman was sitting earlier. At the bank, he is formally humiliated and sacked for causing the first run on the bank since 1773 (it is stated that the bank supplied the money for the shipment of tea destroyed in the Boston Tea Party, during which the colonists tossed the tea into Boston Harbor, "rendering it unfit for drinking, even by Americans," Mr. Banks awkwardly jokes). However, after being at a loss when ordered to give a statement, Mr. Banks invokes Mary Poppins' all-purpose word "Supercalifragilisticexpialidocious!" to tweak Mr. Dawes. He gives Dawes the tuppence, tells one of Uncle Albert's jokes, and raucously departs. Dawes mulls over the joke, finally "gets it" and floats up into the air, laughing.

The next morning, the wind has changed direction, and so Mary must depart. Meanwhile, the Banks adults cannot find Mr. Banks, and fear that he might have become suicidal. However, Mr. Banks, now loving and joyful, reappears with the now-mended kite and cheerfully summons his children. The greatly relieved Mrs. Banks supplies a tail for the kite, using one of her suffragette ribbons. They all leave the house without a backward glance as Mary Poppins watches from a window. In the park with other kite-flyers, Mr. Banks meets Mr. Dawes Jr., now in charge of the bank, who says that his father literally died laughing. Instead of being upset, the son is delighted his father died happy and re-employs Mr. Banks (Andrew Bunny to fill the opening as junior partner. Her work done, Mary Poppins (Dashi Dog) takes to the air with a fond farewell from Bert (Shellington Sea Otter) (who was selling kites), telling her not to stay away too long.