Commuting to and from work each day is the norm for millions of people - the train chugging along, never getting a seat and having elbows whacked into your stomach, all before 9am, is part and parcel.

But what if something as mundane as a train journey spawned a sinister and dark obsession? This is the basis for Girl on the Train, Paula Hawkins' global bestseller and arguably one of the most anticipated movies of 2016.

The novel topped bestseller lists worldwide and has been on the New York Times charts for 82 weeks.

Stars of the film descended on London's Leicester Square for the world premiere last week and the movie lands in cinemas on October 7, but there will be previews showing on October 5 and 6 - here's everything you need to know before going to see it.

Emily Blunt at the world premiere of The Girl On The Train at Leicester Square, London.

What's it about?

The edge-of-the-seat thriller is about a train passenger who thinks she has witnessed a murder and becomes obsessed by it.

Emily Blunt, plays lead character Rachel Watson, a barely functioning alcoholic who is struggling to get over her divorce from ex Tom (played by Justin Theroux).

Her excessive drinking brings on blackouts and when she wakes up she has huge gaps in her memory.

Rachel becomes obsessed with a couple she sees on her daily commute, but one day something truly horrific happens and her life is turned upside down.

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Who is in it?

The Devil Wears Prada star Emily Blunt, plays Rachel, a drunk whose life is slowly spiralling out of control. Blunt first discovered the book through her sister Felicity who is a literary agent.

Rachel's ex-husband Tom is played by Justin Theroux - Jennifer Aniston's husband and journalist Louis' cousin.

Swedish actress Rebecca Ferguson plays Tom's new wife Anna. She earned a Golden Globe nomination for her role in The White Queen and was also in Mission Impossible: Rogue Nation.

Haley Bennett (The Magnificent Seven) and The Hobbit actor Luke Evans play Megan and Scott - the couple Rachel becomes obsessed with on her daily commute.

Friends actress Lisa Kudrow also makes an appearance as Monica, a co-worker of Tom's.

Author Paula Hawkins (left), with Emily Blunt (second left), Rebecca Ferguson (second right) and Haley Bennett (right) attending the world premiere

London to Manhattan?

Whilst the novel is set in the outskirts of London the film makers opted to set the thriller in Manhattan. The change in location annoyed fans of the book with many people believing the setting should have remained the same.

Despite the move author Paula told the Sunday Times “I’m not really concerned about the repositioning as I think it is the type of story that could take place in any commuter town.”

When is it out?

Girl on the Train is released in cinemas Wednesday, October 5.