Marian Keyes Rocks! Reasons Why You Should Read The Mystery of Mercy Close. Plus five signed copies to be won

Marian Keyes's long-awaited return to fiction has been a huge success - and rightly so. Never tried her books before and not sure whether this is for you? Here are eight reasons why you should read it.

1. It's the return of the Walsh family. First seen in Marian's debut novel Watermelon, the various Walsh sisters have starred in some of her best-loved books. Snarky youngest sister Helen finally takes centre stage in The Mystery of Mercy Close, and it was worth the wait. Because...

2. ...The Mystery of Mercy Close features one of the most uncompromisingly brilliant heroines in commercial fiction. Helen is grumpy, spiky, unfriendly, and capable of holding a serious grudge against a child. She's also hilarious. Partly because...

3. It introduces the Shovel List. “It’s more of a conceptual thing,” explains Helen. “It’s a list of all the people and things I hate so much I want to hit them in the face with a shovel.” This list includes music (yes, all music), hot drinks and active aging. As a private investigator, Helen does not approve of the older members of the population going out and doing exciting things when, as far as she's concerned, they should be sitting in their front rooms staring out the window all day, seeing things that could later be useful to her investigation.

4. It's a genuinely thrilling mystery. Helen is hired by her ex-boyfriend Jay to find Wayne Diffney, a member of the boyband Laddz who has disappeared from his house in Mercy Close just a few days before the group’s big comeback concert. There's a lot of money riding on the gig, and Helen's search leads her to some strange and dangerous places. I was enthralled by the quest for Wayne, and I hope Marian writes more mystery stories - she's definitely got the knack.

5. It's a brilliantly evocative and very moving depiction of living with a serious depression. Helen's illness is described so well that even someone who's never experienced depression or anxiety should understand what she's going through. “Everything looked ugly and pointy and strange and I felt like I was living in a science fiction film,” says Helen. “Like I’d crashlanded into a body that was similar to mine and onto a planet that was similar to earth, but everything was malign and sinister. I felt like all the people around me had been replaced with doppelgangers. I felt very, very not safe. Uneasy was the most accurate description of how I felt, uneasy to the power of a million.”

6. It's not sentimental. There's no easy fix to Helen's depression. But there is hope that she'll be able to live with it.

7. It's very, very funny. Helen herself is a fantastic, blackly comic creation, but some of the best laughs are courtesy of the glorious Mammy Walsh. At one stage she starts talking in an unusually sassy way (and addressing her daughter as "girlfriend!"). “Why are you talking like that? What shows have you been watching?” asks a suspicious Helen. “Ah, you know, the usual," says Mammy Walsh. "America’s Top Model. Whatever is on.”

8. It's a pitch-perfect picture of modern Ireland, from the middle class love of pretentious Farrow & Ball-esque paint colours to the consequences of the financial crisis (when we meet Helen she's just lost her beloved flat because she can't afford to pay the mortgage and has been forced to move home with her parents).

And did I say it was funny? And moving? And exciting? Because it is. Go on, read it.

And to make things even better we have FIVE signed copies of the book to give away.  Just leave us a comment with the title of one of the posts Marian has written for Beaut.ie and we'll enter you in the draw! (Winners will be chosen at random from the comments; you must be over 18; no cash alternative is possible and our decision is final. Comp ends OCT 28 5pm)