Readers in the know may recognise Ali Ahearn as Harlequin Medical super-author Amy Andrews. This is her first foray into mainstream fiction - a story co-written with her sister about sisters. Though I think it’s probably fair to say that there’s not a whole lot going on that’s autobiographical here.

Joni is a blue-haired free spirit with some cash flow problems. Frances is uptight, upright, and absolutely miserable. The two have been estranged for years, ever since Joni committed an unforgivable sin. The only link they have is their beloved grandmother who still sees them once a week - just on different days. When she dies, they are both devastated. When her will is read, they are both enraged. To collect the million pounds each has inherited, they  have to participate - together - in a Survivor-esque game show off the coast of Australia called ‘Endurance Island’.

The money is more than just money to both of them: it offers a chance to escape, to build their lives, to invest in something they believe in. But the pain of having to reunite does not make the decision - or the ensuing competition - easy.

What surprised me most is that, although I’m very familiar with Amy Andrews’s work, I couldn’t pick which character she was writing. Though this novel is jointly written, the transitions between characters and the style and flow of the writing is so smooth it never shows. Whether because the two writers are close, or just some darned good editing, if not for the two names on the front, the reader would never guess this was a shared venture.

Though there is romance in the course of the story for both sisters, this isn’t a romance novel - it’s a sister novel. The biggest and most important relationship is between Joni and Frances, and indeed between Joni and herself, and Frances and herself, and that focus is never undermined. If the authors took the romance out, the reader would never have missed it.

The biggest frustration that I can see for readers is that if Joni and Frances just took one of the rain-soaked nights and talked about what was going on, then everything would be solved. However, it’s very much within the characters and their history that they don’t talk, even when you just wish they would say something already. And though a conversation would clear the air, it’s also clear that Joni and Frances need some time to heal as well, and their month (or so) on the island lets them do that in a way that’s both confronting and organic, and well conveyed to the reader.

Bottom Line: Not your average chick lit, and will be particularly affecting for women who have sisters (and who fight with their sisters). While dealing with some pretty heavy subjects, in particular Joni’s battle with addiction, Sister Pact is never cumbersome, but rather a reflection of hope and of a future, even when the past seems to be overwhelming.