I thought I knew what to expect from an Elizabeth Cadell novel, but this was the book that proved me wrong.

It had her usual ingredients:

• A bright, independent heroine.
• An overseas jaunt.
• A puzzle to be resolved.
• A dash of romance.

But the balance was rather different – tilted less towards the romance and much more towards the puzzle – and the story was much darker than I had anticipated.

Think somewhere between D E Stevenson and Mary Stewart with a dash of Agatha Christie ….

Gail Sinclair was a secretary, employed by the century-old publishing firm of Beetham Brothers, and because she was poised, elegant and capable, it fell to her to look after Mrs Stratton.

Mrs Stratton was a young widow, and, while she was nursing her dying husband, she had written a book that was expected to become a publishing sensation.

The job should have been easy, but there was a complication: Mrs Westerby.

Mrs Westerby was the sister of Mrs Stratton’s late husband, and she was determined that she and Mrs Stratton should be the best of friends, that they would be able to comfort one another after their shared loss. But she was brash and loud, she was chaotic, and she was inclined to turn up wherever Mrs Stratton was, quite sure she was wanted, oblivious to the fact that she was not.

Mrs Stratton was everything that Mrs Westerby was not, she was her complete opposite, and she just wanted to live her own life in peace. She saw no reason to have a relationship with a sister-in law who was years older than her, who she barely knew, when the man who had been the only link between them was gone.

Mrs Westerby discovered that Gail’s married sister was a near neighbour, and extended an invitation to Gail. She couldn’t say no; and strangely, for all her failings, she couldn’t help rather liking Mrs Westerby ….

Gail planned to use her annual leave to travel to Spain, to collect her naval-officer brother. When Mrs Stratton found out she asked a favour. She wondered if she might travel with Gail, as far as the property her husband had owned in the Basque Country. Mrs Westerby had been left the house, Mrs Stratton had been left the furniture and they needed to sort things out. Mrs Westerby was going too, but Mrs Stratton really did not want to travel with her. Gail was reluctant to get involved, but she didn’t feel she could say no.

The journey was eventful to say the least, and Gail and Mrs Stratton kept running into Mrs Westerby and Julian, the godson who was driving her. Mrs Westerby’s behaviour grew more outlandish, more suspicious.

Gail knew what she thought, but Julian saw things rather differently.

There is, of course, a grand dénouement at that property in the Basque country.

That ending was a little bit contrived, but I couldn’t have predicted it and I do think it was right.

The plot was a little bit clunky, but I didn’t really mind.

The story was engaging.

The character-study, the contrast between the sisters-in-law, was intriguing.

The puzzle was exceedingly puzzling, I was genuinely baffled, and I loved the way the story held me, enjoying the journey and the incident as I wondered what on earth was going on.

All of that came together to make a book that was ridiculously readable.

And a very fine entertainment.