13 Reasons Why is the most talked-about show on Netflix so far this year. Tackling suicide, mental health issues and sexism, it isn’t afraid to look at the big issues – yet it’s so engrossing and accessible that it’s perfect material for binge-watching on Netflix.

So before you settle in to Hannah Baker’s story, here’s what you need to know:

What is 13 Reasons Why about?

Based on the bestselling 2007 novel by Jay Asher, the premise of 13 Reasons Why is that main character Hannah Baker mysteriously killed herself – and left a series of cassette tapes, each side dedicated to one of the 13 reasons why she committed suicide.

She wanted the characters who are seemingly involved in her decision to listen to the tapes, and the show focuses on her friend Clay Jensen who is next in line to go through them.

Gripping, heart-breaking and often a difficult watch – this Netflix drama has got everyone talking.

How is Selena Gomez involved – and why isn’t she in it?

Katherine Langford, Selena Gomez and Dylan Minnette

The Disney actress and pop singer was originally set to star as Hannah – when it was due to be a feature film in 2011. However, the decision was taken that it would become a TV series and Selena instead became an executive producer on the project.

“I see myself as Hannah so much. Seven years ago I did and even more so today,” Selena told The Hollywood Reporter.

She continued: “A book is frightening for me because I know the cult following it has, which is the reason why I didn’t want to be in it.”

But fear not, Selena fans – she features in the commentary which you can watch after you’ve completed the series.

So who is Katherine Langford?

Katherine Langford, who stars in 13 Reasons Why as Hannah Baker

The Australian actress (yes, we know – she completely nails the American accent so much that we didn’t realise either) stars as central character Hannah.

The 20-year-old snagged the role after an unusual audition – via Skype, from her home town of Perth – and didn’t meet the producers until she was cast.

It’s easily her biggest role to date, with her only other notable appearance in a short film called Daughter, which premiered at the Cannes Film Festival in 2016.

Who are the rest of the cast?

Miles Heizer, Dylan Minnette and Devin Druid

Katherine’s co-star is Dylan Minnette, whose character Clay Jensen is central to discovering what happened to Hannah. If you recognise him, it’s probably from his role in the feature film Let Me In – the US remake of Swedish horror Let the Right One In – in which he played a bully called Kenny. He’s also had minor roles in Labor Day and Fred Claus.

Another familiar face is Kate Walsh – the Grey’s Anatomy actress who plays Hannah’s mother.

However, most of the cast was relatively unknown in the UK before the series hit Netflix. Sure to be future stars are Justin Prentice (who plays sports player and typical jock Bryce Walker), Miles Heizer (Alex Standall), Alisha Boe (Jessica Davis, who becomes friends with Hannah and Alex as they are all new to the town), Christian Navarro (Clay’s friend Tony Padilla – and he also played Jorge in four episodes of retro music series Vinyl), Ross Butler (fellow student Zach Dempsey), Brandon Flynn (Justin Foley, who dates Hannah) and Devin Druid (school photographer Tyler Down).

Will there be a second series?

Though nothing has been confirmed as yet, the overwhelming success of the first season has led to widespread speculation that there will be a follow-up season.

These rumours have been fuelled by cast member Ross Butler (Zach) pulling out of another TV show, Riverdale, because of "commitments to other projects".

So how can I watch 13 Reasons Why?

The full series is available now on Netflix via your BT TV box.

Browsing and watching Netflix directly through your BT TV box is quick and easy. Press the YouView button on your remote, go to Players & Apps, select Players and click on Netflix.

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