Oh, waily, waily.

The Shepherd’s Crown (2015) — by English author Sir Terry Pratchett, featuring his young witch character, Tiffany Aching — was never going to be an easy read for me. I knew and counted Terry among my friends since 2008, and I watched Alzheimer’s slowly and insidiously strip him of attributes and faculty over that time.

The 41st and final Discworld novel — published five months after its author’s death — wasn’t something I ever wanted to face.

But I am glad I did. It’s a joy to read. Terry knew in 2014 that this was the likely curtain call for his time on the Disc.

He was still incubating ideas for future books. He wasn’t quite finished with Sam Vimes or the wizards of Unseen University — but he was a very clever and, above all, realistic man.

So what can we make of this final book?

The fifth instalment of the Tiffany Aching series sees Tiff assume a greater mantle of responsibility than ever before.

She’s no longer the little girl we first met in the wee free men; nor is she the apprentice, trainee or P-plater of her second and third and fourth outings. She is now the Witch of the Chalk, and events conspire to ensure she yet must become much more.

Shepherd’s Crown wasn’t an easy write for Terry. Rob Wilkins’ afterword to the book hints both at that and that there was still more finishing to be done on this novel, had there only been more time.

We can only wonder what that may have been. It’s little wonder that Death himself — an anthropomorphic character in Discworld — does his duty with sorrow in this book.

Neil Gaiman has hinted at an alternate ending which Terry never had a chance to pen. I know that Terry always wanted to do more, to refine the words again and again.

In this book he tips his famous hat to a swathe of older, much-loved characters as the consequences arising from the death of one of his greatest creations ripples throughout their fictional world.

I once asked Terry why he hadn’t killed off a particular character before. He looked at me askance, and said:

If I did that I wouldn’t be able to write more books about them.

There are no more books to come and Terry takes steps in this final novel that he never contemplated before.

He carries off another ripping yarn with aplomb; the wit and humour we have come to love over 32 years and 41 visits to the Discworld are all there.

He excelled at gallows humour and a simple two-word edit to a very familiar phrase raises a hearty laugh when tears are infinitely more appropriate.

Tiffany faces off against an old, old foe, but it is not just the formidable powers of this young and now leading witch that save the day: the passage of time, the relentless advances of progress and life itself all play a role.

The consequences of the actions of many others, characters new and old, across years of Discworld narrative are all neatly interweaved and seamlessly push the plot of this book forward.

This is not a fantasy novel intended for “younger readers” as it is wont to be pigeonholed. I assert that with confidence, even though it contains witches, a man who wants to be a witch, wizards, a woman who was once a wizard, wily cats, counting goats, pictsies, goblins and the most malevolent of fairies.

This is a book for all ages, the tour de force of one of the English language’s greatest authors, who, in the midst of encroaching darkness and facing so many terrors of his own, has contrived to astound us one last time with his craft.

Terry’s razor-sharp insight to the human condition, through an unusually turtle-shaped) lens remains strong.

Pratchett liberally sprinkles his text with instructions to his readers — read books if you want to learn things, make choices when faced with them, stand your ground, don’t tolerate the intolerable from others. Simple, yet sound advice for life.

For those of us who long for more, we will have only the realm of our own imaginations and a rich and deep seam of wonderful words to mine again and again.

Alzheimer’s robbed the world of one of is brightest lights last March. No-one could replace Terry, never in a hundred years, but, as Nanny Ogg, Pratchett’s witch from the Ramtop Mountains, gnomically put it: