There is a line in An Improbability of Puffins that stayed with me after I wrote it.

"Birds knew first."

It began as folklore. That seemed right. People have always watched birds for signs because birds spend their lives answering questions we have become very good at ignoring; Where is the food? What has the weather changed? Is this still safe? When do we leave? When do we return?

On Scilly, those questions matter. Weather is not background there. It decides boats, work, post, school trips, rowing, bread deliveries, and whether someone gets home before dark. A small change in wind can alter a day. A fog bank can make the familiar strange. People read the sky, of course, but birds read it first.

The novel has puffins at its centre. That was always going to be true. They are awkward and brave and oddly formal, with their bright bills and serious little faces. They vanish for much of the year, living somewhere beyond the edges of human sight, then come back because season and body tell them it is time.

Yet other birds kept arriving as I wrote. A robin at a bakery window. Swallows crossing a field. Starlings on a roof, stealing sounds from the world around them. Goldfinches bright in the hedge. Each behaved differently. That interested me more than turning them into symbols and making them stand still.

Robins defend. Swallows return. Starlings borrow. Goldfinches gather. Puffins disappear beyond the horizon, then come back to land because something older than language has called them in. Birds are already carrying enough story without a novelist making them speak.

Beryan understands this better than most of the adults. She watches. Counts. Films. Checks dates. She wants to know what changed before everyone agreed that something had changed. She does not trust the tidy version. She wants the rougher truth underneath it.

That is where birds become useful. They live beyond our explanations.

A council can amend a report. A family can decide not to discuss a year. A story can be polished until nobody remembers the rougher version and the birds continue with weather, food and route. Or they don't. An empty sky can become evidence. So can a return. A missing colony is not just a sadness. It is a question. What altered? What failed? What did we stop noticing because the explanation was easier than the looking?

I am wary of making nature too convenient in fiction. A bird should remain a bird. That is part of its power. It does not arrive because a character deserves hope. It has its own reasons. It lands. Looks. Calls once. Leaves. The person standing beneath it must decide what that means.

Perhaps nothing. Perhaps everything. That is how folklore often works, I think. Not as a fixed answer, but as a way of paying attention. A story begins because someone saw a bird lift before a storm, or return to a place everyone had called empty, or fall silent when the air changed.

The bird has already moved on. The person is left with the meaning.

Puffins are almost too easy to love, and baby puffins are called pufflings, so you can see why children love them.

I will always remember seeing my first puffin, it looked almost two-dimensional on the waves as I stood and watched from The Sea King. It was unreal. Puffins have small bodies, serious expressions, and beaks of extraordinary living colour. They look faintly improbable even before they do anything, perhaps because they carry contradiction so well. Comic and solemn, awkward on land, astonishing over water, small enough to overlook, yet stubborn enough to cross an ocean and come back to the same piece of rock year after year.

In a novel concerned with homecoming, memory and damaged routes, I couldn't really have asked for a better bird. Besides, there is something pleasing about giving a serious lighthouse mystery an improbable number of puffins.

I didn't want the birds in An Improbability of Puffins to sit around the edges of the story looking picturesque. Scilly has enough beauty without fiction arranging extra decoration. The birds are not there for decoration; they are a key part of the evidence.

Birds notice a place differently from us. They don't care what a council meeting minute says happened. They don't read the plaques and they don't respect the neat version of an old story, or spread gossip and rumour. They return to food, rock, weather, season, route and burrow. Or they don't.

Beryan begins watching puffins because she wants facts. Burrow counts, dates, footage, and patterns. She has grown up around people who can turn almost anything into an island story, and others who know the folklore of old Scilly.

Then the gaps begin to interest her, and she wants proof of what is happening.

A missing bird. An empty burrow. A date that doesn't fit. A description that’s not quite right. A pattern nobody bothered to write down. That became useful to the novel because absence can be evidence too.

There are other birds throughout the book. Robins defend their patch. Swallows return. Starlings borrow sounds and the finches get everywhere. Scilly is a well-known destination for birdwatchers from all over the world, each bringing their own version of myth and magic.