I believe I do have a timeline of events that you might find informative.
In the poem, Jerry tells the audience of the years he spent living with Newt during the war. It was there that Jerry first started writing rhymes, for which Newt would pay him a ha’penny each (on condition that they scan).
Well, since you ask me for a toast…
O Nightingale! O Uncle Newt!
Jerry is partly disappointed by this news. This means he will stop living with Uncle Newt, who has been teaching him to write poetry.
After first hearing Jerry’s latest poem, for which Jerry is paid his standard ha’penny, Uncle Newt gives him his birthday presents.
Jerry opens a gift to find a kazoo, which Uncle Newt admits he had just found at the back of a drawer.
Uncle Newt encourages Jerry to blow the kazoo, which cues Newt to deliver a “paean of praise” that he has written for Jerry. The paean tells of Jerry’s accomplishments and good deeds while living with his uncle.
Unbeknownst to Jerry, his mother, Vanessa, has taken leave from her war service, so that she can visit. She arrives in the room as Uncle Newt is finishing his paean. She delivers the final word: “Surprise!”
When asked by Jerry, Uncle Newt explains that a paean is “a long poem about how wonderful you are”. Jerry asks if he can have one. Uncle Newt tells him that he can maybe have one for his birthday.
They wish each other goodnight, to which Jerry adds: “Don’t let the bedbugs bite.”
Jerry’s daughter has just spoken to him to ensure that he will not do a poem at the funeral. When Uncle Newt hears this, he suggests that Jerry should do one for Newt’s own funeral, when the day comes.
Uncle Newt says that he would pay Jerry his fee for the poem in advance, except that ha’pennies are no longer produced. He reacts with mock outrage when Jerry suggests that he pay him a whole penny instead.
The man tells him they have never met, but that he had always wanted to meet him. He then recites this short poem:
I had a walrus for a pet.
Why I bought it, I forget.
I fed it kedgeree and rusks,
And used best Blanco on his tusks.
From the style of the rhyme, Newt recognises it as something written by himself or Jerry. He remarks that animals and kings were their speciality.
Newt is gratified to hear that the man had remembered the verse for all these years and that it had “worked”.
Newt deems the verse worthy of the standard ha’penny fee, but also offers some advice for improvement.
Spencer explains that the SOE communicates with field agents using “poem codes”. The message sender and recipient encrypt their messages based on an agreed upon passage of text. For security, this text must be carried in the agent’s head, but not be something well known generally.
The passages need to be intensely memorable, unpredictable and, ideally, consist of twenty-six words.
Spencer recalled the rhymes that Newt used to teach him in class as memory aids, and thought that Newt could help with this. He tells him that suitable passages were in great demand.
Newt is amused and honoured by the idea that his nonsense poems could help with the war effort. He agrees to help and adds that he will also enlist the help of his nephew, Jerry.
He explains that Aristotle was wrong to claim that heavy things fall faster than lighter things. He uses a short poem to remind them of this:
Whether they’re large or whether they’re small,
Has no effect on the rate which things fall.
But whether you choose to accept this or not-le,
Depends on your faith in that fool, Aristotle.
He asks one of his students, Spencer, who it was that proved Aristotle wrong in 1592. Spencer, who had not been listening, incorrectly guesses Plato. The answer was Galileo.
Deborah is surprised to hear Jerry ask if he should start his speech with a poem, since she had just assumed that he would.
Vanessa and Deborah swap theories about the marital status of the registrar at the service, based on their observations of biro marks and reading glasses.
As they travel, Russ starts to feel unwell. Uncle Newt offers his top hat, should it be needed.
In an attempt to distract Russ, they all start to play a storytelling game by each saying one word at a time, but this fizzles out as Russ feels worse.
Next, they try to think of a song which they all know so that they could sing it to Russ. Uncle Newt is too elderly to know Yellow Submarine and Deborah is too young for Knees Up Mother Brown, but there is one song which spans the generations of the family.
Jerry counts them in and they all sing Woof, Woof, Woof together.
Unfortunately, they cannot prevent the inevitable, and Deborah is forced to apologise to Uncle Newt.
Newt replies: “Oh, not at all my dear. It was a very old hat.”