Broadchurch series two has been shrouded in secrecy...until today. This afternoon brought us the very first trailer for the brand new series which returns to ITV on Monday 5th January. 

So, what have we learned? 

The minute-long montage plays like a music video, with ethereal vocals and haunting music accompanying the angst-ridden residents of Broadchurch. And that "other story" Chris Chibnall wanted to tell? Well, it appears to be that of Sandbrook. 

The trailer opens with David Tennant and Olivia Colman – as DI Alec Hardy and DS Ellie Miller – sitting on a bench in a scene not dissimilar to the end of the first series after *spoiler alert* Ellie's husband Joe was unveiled as Danny's murderer. 

But the action soon switches to an ashen-faced Hardy who gives us the first proper clue as to what series two has in store with a flashback to a young girl wearing a pendant. Cast your mind back to series one and you'll recall Hardy's disastrous Sandbrook investigation where a crucial piece of evidence – a pendant – went missing, leaving the case to collapse, a killer on the loose and a disgraced detective.

Hardy's flashback also contains what appears to be someone drowning, although extra brownie points go to any eagle-eyed reader who can work out who. 

The Sandbrook case centred around the murder of two young sisters, seemingly referenced by Ellie later on in the trailer when she asks, "Where were you both the night those girls disappeared?" To whom is yet another mystery, but new cast member James D'Arcy is shaping up to be a potential suspect in the unsolved case, seen here telling Hardy, "I want my life back"...

...after getting beaten up by a mystery assailant:

The stress is clearly taking its toll on Hardy once again as he's seen pleading with Ellie: "I can't do it on my own". 

But poor Ellie's got plenty on her plate with two young children to look after and – by the looks of things – is still the target of Beth Latimer's (Jodie Whittaker) grief which remains a prominent feature of this series: a brief glimpse of a scene beside what looks to be Broadchurch's graveyard suggests we could be revisiting her son Danny's final resting place.

The first trailer also affords us glimpses of more of the new cast members, including Charlotte Rampling who is seen on the beach with Mark and Beth Latimer, suggesting she could perhaps be Mark's mother, come to Broadchurch to lend a helping hand to the grieving family? 

We also get a very brief glimpse of an exasperated Marianne Jean-Baptiste...

...but it's Eve Myles' character who provides the most intrigue, imploring a mystery someone with the words, "tell her". 

Who and what are yet to be determined, but the next two frames suggest the Hardy and Miller relationship is yet again riddled with secrets: 

Alongside the exciting newcomers are returning cast members Carolyn Pickles (Maggie), looking shifty as she peeks inside a window... 

And her young reporter Olly Stephens (played by Jonathan Bailey) striding purposely in the opposite direction from a mystery figure. 

Arthur Darvill's Reverend Paul Coates also plays a part in the new series. Here he is looking like he's getting to grips with yet another Broadchurch tragedy...  

The Latimers also feature heavily in the new trailer which includes a heavily pregnant Beth suggesting the second series picks up roughly six months after 2013's dramatic finale. Danny's grieving mother is briefly pictured sobbing in the stairwell of what could be a hospital, police station or court room.

The latter would tie in neatly with the footage of her with husband Mark (Andrew Buchan) and daughter Chloe (Charlotte Beaumont), smartly dressed and surrounded by a scrum of photographers – perhaps en-route to Joe Miller's trial? 

And finally...the bluebells. Near the start of the trailer we witness a stone-faced Ellie gravely handling a piece of card with either a pressed or hand-drawn bluebell.

And – in the closing moments – the same flower appears again, this time in a woodland, trampled on by a mystery stroller accompanied by the words "new secrets". 

And so, the mystery continues... Do you agree with our theories? Do you have any of your own? Share below – and don't forget to put the date in your diary: Broadchurch is back on Monday 5th January.