This is the fifth book in Lucinda Riley’s Seven Sisters series based loosely on the mythology of the star cluster known as Pleiades or ‘the seven sisters’. Each novel tells the story of one of the adopted daughters of a mysterious millionaire known as Pa Salt.

The girls come from different cultures and backgrounds, but all grew up together on Pa Salt’s estate in Switzerland. They are each named after one of the stars in the cluster – Maia, Alycone (Ally), Asterope (Star), Celaeno (CeCe), Taygete (Tiggy) and Electra D’Aplièse. You may have noticed that there are only six sisters; for some reason, which we don’t yet know, a seventh was never adopted. This is one of many mysteries running throughout the series.

At the beginning of the first novel, The Seven Sisters, Pa Salt died, leaving each sister some clues to help them trace their biological parents. So far we have heard Maia’s story, Ally’s, Star’s and CeCe’s; now, in The Moon Sister, it’s the turn of Tiggy. All of the books in the series work as standalones and it’s not essential to read them in order, but this book does overlap with one or two of the others and advances some of the storylines begun earlier in the series.

The Moon Sister follows Tiggy as she begins a new job in the Scottish Highlands, where she has been employed by Charlie Kinnaird to establish a colony of wildcats on his estate. With her degree in zoology and her love of nature, Tiggy is perfect for the job and quickly settles in, getting to know the animals on the Kinnaird estate and forming a close friendship with Cal, the man whose cottage she shares. The peace is disturbed, however, when Charlie arrives with his troubled teenage daughter and his spiteful, vindictive wife.

Away from the problems in the Kinnaird household, Tiggy meets Chilly, an elderly gypsy who lives alone on the estate. It seems that fate must have brought them together, because Chilly is the one person who knows the truth of Tiggy’s origins and can point her in the direction of her birth family. From Chilly, Tiggy learns of her ancestor, Lucia Albaycin, a famous Spanish flamenco dancer. But Chilly doesn’t know everything, so to discover the rest of her family’s story, Tiggy must travel to Spain and visit the gypsy community in the caves of Sacromonte.

Like the others in the series, this book is divided between the modern day storyline and the historical one. We spend a decent amount of time with each character before switching to the other, which means we can become absorbed in both stories. Lucia’s story is fascinating – I can’t say that I liked her, as I found her very self-centred and driven by ambition at the expense of everything else – but she is certainly a strong character, whose power and passion as a person is matched by the power and passion of her dancing. It was interesting to watch as she (along with her equally selfish and irresponsible father) start from nothing to build a successful career in flamenco which takes them all over the world. Meanwhile, in Sacromonte near Granada, we follow the sad story of how the lives of the other gitanos (Spanish gypsies) are affected by first the Spanish Civil War and then the onset of the Second World War, leaving their community changed beyond recognition.

It was good to get to know Tiggy better too – and she is much easier to like than Lucia. The other d’Aplieses think of her as the sensitive, spiritual sister…the sort of person who wants to help everyone around her, whether human or animal, and who cares deeply about nature and the environment, trying hard to resist temptation and stick to her vegan diet! Of all her sisters, Tiggy is particularly close to Ally, whom we met in The Storm Sister, and it was lovely to see her again in this book. The one part of Tiggy’s story that didn’t really work for me was the romance. I felt that she and the man concerned hadn’t spent enough time together for their love for each other to develop, so I didn’t become as emotionally invested in their relationship as I would have liked.

The next book is going to tell Electra’s story and I have to admit I’m very apprehensive about that one. From the little we’ve seen and heard of Electra so far, her personality strikes me as very unappealing. However, we are given lots of intriguing clues in The Moon Sister regarding Pa Salt, his death and some strange occurrences at his home, Atlantis, so I’m hoping Electra will fill in some more of the gaps for us. I’m also curious about the rich businessman Zed, who keeps popping up throughout the series, trying to worm his way into the lives of first Maia, then Tiggy and now, it seems, Electra. For those reasons, I will be looking out for the next book, which I’m hoping will be published later this year.