Later the same day there is a dramatic drop in the temperature. After a frustrating session in the studio, where nothing seems to want to go right, Tilda shares the last tin of chicken soup with Thistle, and the two of them retreat to the sitting room. Tilda banks up the fire, wondering how long the log supply will last if she has no central heating to back up the wood fires and stoves in the house. She pulls cushions off the small sofa and hunkers down on the rug as close to the crackling flames as is sensible, with Thistle curled up beside her. She has lit a paraffin storm lantern, which smells more than a little, and gives out a low light that is helpful, but not steady or strong enough to read by. A moment of inspiration drove her to dig through the unpacked box of camping gear to find a headlight. Tilda has put new batteries in it and adjusted the headband to make it as comfortable as she can, and now the thing provides a narrow beam that neatly illuminates a page at a time as she leafs slowly through the books Professor Williams lent her.

The images of Celtic knot-work are quickly becoming familiar to her. There are standard shapes and patterns that seem to have been employed in a variety of ways. Animals, birds and flowers are often incorporated into the designs, twisting and entwining with one another, their heads and bodies stylized and elongated, their eyes always watchful and sharp.

Yes, these. On my pots, these would work. The animals, in particular, I think.

But it is too late in the day, and too dark in the sitting room, to attempt sketching. Instead she puts the book aside and chooses the next. A moment’s turning of the pages reveals impenetrably dense text regarding the history of the lake. Tilda feels unequal to the task of reading it. She knows there must be fascinating facts hidden somewhere in the plodding prose, but she is not in the right state of mind to tackle it.

The third book is the one the professor chose for her, almost as an afterthought. Only now has she had the chance to look at it. She reads the title out loud to Thistle.

‘“Myths and Legends of Llyn Syfaddan.” Hmm, what d’you reckon, girl? Might answer a few questions?’