We’ve always been a little wary of water’s hidden depths and our suspicions were confirmed by the body count in the first series of Annika, Alibi’s suspenseful coastal crime drama. Even so, we couldn’t help but be gripped by this series following Glasgow’s Marine Homicide Unit (MHI) as they investigate cases of murder in and around Scottish waters.

That’s down to the show’s twists and turns, witty script and – most of all – the delightfully wry performance from Nicola Walker (Unforgotten) who plays the unit’s director, Detective Inspector Annika Strandhed. Every time she breaks the fourth wall to deliver a droll aside or make a literary reference (in series 1, she riffed on Moby Dick and a play by Henrik Ibsen), it’s an unexpected hoot.

What happened in series 1 of Annika?

A Norwegian native and supercop, Annika is drafted in to head the newly established marine crime-solving unit based in Glasgow. Faster than you can say “watery grave”, she’s dispatched with her team to solve the mystery of a body found in the Clyde. Clever and capable, Annika is determined to make our shores a little bit safer – though it will take time to earn the grudging respect of DS Michael McAndrews (Jamie Sives, Guilt), who feels the job should have been his.

She is also a single mum, frequently at odds with her brilliant but tempestuous teenage daughter, Morgan (Silvie Furneaux, Red Rose) and contending with her inconvenient feelings for Morgan’s therapist, played by former Doctor Who actor Paul McGann.

What’s ahead for Annika in series 2?

A new series of Annika will set sail on Alibi on 9 August, when the MHI will be called upon to investigate more unsettling deaths in Scottish waters, from the Hebridean Isles to the capital city of Edinburgh. There’s a creepy case involving a millionaire found dead in his shark tank, and a violent drowning captured on a mobile phone.

Luckily the Marine Homicide Unit will be there to investigate these cases and more, with Annika at the helm of her slightly dysfunctional team. As well as McAndrews, this includes data-driven DC Blair Ferguson (Katie Leung, Harry Potter) and lone wolf cop DS Tyrone Clarke (Ukweli Roach, The Midwich Cuckoos). There’s a new recruit, too: DC Harper Weston, played by Andor actor Varada Sethu.

In Annika’s personal life, there are rough seas ahead thanks to a shocking revelation involving the identity of Morgan’s father in the series finale. And Annika’s own father, played by Norwegian actor Sven Henriksen, will be joining the family fold.

Where else have we seen the star of Annika?

Actor Nicola Walker has been gracing our screens with excellent performances in memorable TV shows since the 1990s – surely that qualifies her for “national treasure” status? And though there’s something about her intelligence and composure that sees her frequently cast as a law enforcer, her career timeline reveals that her range extends to farming, boardroom wheeling and dealing, religious leadership, complicated family sagas and more.

When is series 2 of Annika 2 on TV?

The new series of Annika begins on Wednesday 9 August at 9pm on Alibi HD (CH 114) and will also be available in On Demand.