Sgt Catherine Cawood is back as Happy Valley returns to our screens this week.

The gritty crime series returns on Tuesday at 9pm on BBC One after almost a two year wait for fans.

Happy Valley series two
Happy Valley series two

Sarah Lancashire stars in the award-winning drama, filmed around Calderdale, Halifax and Huddersfield.

Whether you're new to the series or excited for its return, we've put together a guide to help you get ready for series two.

Here's everything you need to know about Happy Valley

What is it about?

Happy Valley follows no-nonsense copper Sgt Catherine Cawood, a dedicated officer leading the Calder Valley policing team. She lives with her sister, Clare, and her eight-year-old grandson Ryan, the son of her deceased daughter Becky.

Sgt Cawood (Sarah Lancashire) in Happy Valley
Sgt Cawood (Sarah Lancashire) in Happy Valley

Catherine goes beyond the line of duty to protect her community, her team and most importantly her family - but while she has no trouble taking down cocky, low-life criminals, her own personal dramas are another matter.

What happened in series one?

SPOILER ALERT: If you haven't seen series one and are planning to catch up, you might want to skip this section.

The first series of Happy Valley centred around a Fargo-style kidnapping gone wrong; local businessman Nevison Gallagher had his daughter Ann snatched by drug-dealing thugs after vengeful employee Kevin Weatherill (Steve Pembeton) wanted a pay rise but was denied.

While Kevin (Steve Pemberton) got involved with some unsavoury characters - like Ashley Cowgill (Joe Armstrong), right
While Kevin (Steve Pemberton) got involved with some unsavoury characters - like Ashley Cowgill (Joe Armstrong), right

One of the hired heavies carrying out the job was Tommy Lee Royce (James Norton), a recently-released drug dealer - and the man who allegedly raped Catherine's daughter Becky, who killed herself shortly after giving birth to Royce's child, Ryan.

James Norton as Tommy Lee Royce in Happy Valley
James Norton as Tommy Lee Royce in Happy Valley

Weatherill tried to stop the kidnap but of course it was too late - Ann was snatched, and Royce went to extremes to evade capture, killing police officer Kirsten and almost murdering Catherine when she tracked down and freed kidnap victim Ann.

Sarah Lancashire as Sgt Catherine Cawood in Happy Valley
Sarah Lancashire as Sgt Catherine Cawood in Happy Valley

Royce went into hiding and murdered accomplice Lewis Whippey (Adam Long), while ringleader Ashley Cowgill (Joe Armstrong) was arrested, cut a deal with police and was murdered for his compliance by an unknown criminal further up the drug-dealing chain. Weatherill was also arrested for his part in the plot.

Joe Armstrong as Ashley Cowgill in Happy Valley
Joe Armstrong as Ashley Cowgill in Happy Valley

Royce ended up hiding away in a canal boat, injured and determined to dodge prison. Having discovered that Becky was dead and Ryan was his son, he set out to befriend his child - with terrifying consequences. Luckily Catherine was able to track him down, rescue her grandson Ryan, and hand Royce over to police to face justice.

What can we expect from series two?

The second series, set 18 months after the first, sees Sgt Catherine Cawood (Lancashire) back heading up her Calder Valley police team, with Tommy Lee Royce (James Norton) behind bars.

Video thumbnail, Happy Valley S2 trailer
Video Loading

It is feared a serial killer is behind a spate of murders — and Catherine makes a gruesome discovery that has shocking repercussions for her and her family.

Meanwhile, Detective Sergeant John Wadsworth (Kevin Doyle) faces his own set of problems, and despite being in prison, Tommy forms a bond with a mysterious female admirer (Shirley Henderson).

Who's in series two?

Catherine (SARAH LANCASHIRE)
Catherine (SARAH LANCASHIRE)

Of course, Sarah Lancashire returns as Sgt Catherine Cawood - but there's some exciting new faces lined up for series two.

Jodie Shackleton (Katherine Kelly)
Jodie Shackleton (Katherine Kelly)

Coronation Street stars Katherine Kelly and Julie Hesmondhalgh play CID officer Jodie Shackleton and midwife Amanda Wadsworth (wife of Detective Sergeant John Wadsworth, played by Kevin Doyle).

Amanda Wadsworth (JULIE HESMONDHALGH), John Wadsworth (KEVIN DOYLE)
Amanda Wadsworth (JULIE HESMONDHALGH), John Wadsworth (KEVIN DOYLE)

And Harry Potter star Matthew Lewis, aka Neville Longbottom, plays Sean Balmforth.

Matthew Lewis plays Sean Balmforth
Matthew Lewis plays Sean Balmforth

Pictures released from the first episode show the return of Siobhan Finneran as Catherine's sister Clare and Rhys Connah as Ryan - who has certainly grown a fair bit since series one!

Who's behind it?

Award-winning writer Sally Wainwright both created and wrote Happy Valley, and is also behind TV hits including Last Tango in Halifax, At Home With The Braith waites and Scott and Bailey.

Happy Valley writer Sally Wainwright
Happy Valley writer Sally Wainwright

She had this to say about series two of Happy Valley: "It is 18 months later, so Tommy has been in prison for a year and a half. He was charged with three murders so he is not coming out. Catherine finds a body in episode one and the rest of the series unfolds from there."

What can I expect?

If series two is anything like series one - a gripping crime thriller with dark, complex characters and plenty of action. Happy Valley contrasts beautiful, sweeping shots of Sowerby Bridge, Hebden Bridge and the Calder Valley with scenes of deprivation, crime and poverty, and explore the social issues behind crime, creating gritty, insightful television.

And of course, set in Yorkshire, it excels in the typical dry wit of the region - some of Sgt Cawood's one-liners are superb.

Where was it filmed?

Sgt Catherine Cawood (Sarah Lancashire)
Sgt Catherine Cawood (Sarah Lancashire)

We'll be keeping a beady eye out during season two for the exact filming locations, but the BBC has confirmed that the series was shot in Hebden Bridge, Halifax, Sowerby Bridge, Brighouse, Elland, Huddersfield, Luddenden, Heptonstall, Holmfirth and Bradford.

How many episodes are there?

Like the first series, there will be six episodes in total, each roughly 50 minutes long.

When is it on?

Happy Valley returns on Tuesday (February 9) on BBC One at 9pm.

Reporter Samantha Gildea will be running a Happy Valley series blog — share your thoughts on each episode via our Facebook page, Twitter, or email Samantha.Gildea@examiner.co.uk