We spoke to Strike stars Tom Burke and Holliday Grainger to find out exactly what they thought about their characters’ evolving bond.

Their working relationship

If The Cuckoo’s Calling first introduced us to Robin and The Silkworm worked to establish her role with Strike, Career of Evil puts the two on a near-level professional footing. After all, it’s Robin who is responsible for business thriving...

"I suppose their relationship is at the point where they’re very much feeling like co-workers, and they’re obviously very close. There’s a shorthand between them. It’s the personal relationship that develops and becomes more questionable as does the working relationship of who’s boss, who holds the shots." Holliday Grainger

For Tom Burke – who plays Strike – it all boils down to this:

He realises he functions better with Robin there.

But what about Matthew?

Robin’s engagement to her overbearing boyfriend Matthew may confound the rest of us but as we rejoin the series, she’s in the middle of wedding planning.

So, what does Robin’s betrothed think of her and Strike’s blossoming partnership?

“People have these situations, don’t they, where people get territorial about their partner’s friendships,” teases Burke.

Grainger is more generous to her on-screen other half:

“He’s her rock," she says. "For him to be her first love who knows her family – there is a sense that he’s kind of the core of her and who she is growing up.”

But…

Now she’s maybe growing into a self that is apart from him. For the first time, he’s not part of this burgeoning career woman, the sort of woman that she’s always seen in herself. So she’s sort of leaving him behind.

There’s also Strike’s highly-strung ex, Charlotte, who Burke is fairly confident will make an appearance.

We hear so much about Charlotte in the past tense and afar and the little messages sent to him – I’m sure that’s going to come to the fore.

Road trip

Without wanting to spoil too much, the lead-up to the wedding doesn’t exactly run smoothly. As Robin’s relationship threatens to combust, she and Strike speed down the motorway in a battered Land Rover Defender to chase down a lead in their case.

What’s interesting about the whole thing is they’ve got the most horrible situation going on and yet it’s this weird little bubble of air for them both – to just be in a car together without having to think. Her whole marriage is up in the air.

As soon as Robin feels like she’s split up from Matthew and they go on a road trip together, it’s that thing of your real life disappears and they’re on an equal footing completely. It's not just the freedom in feeling like she might be single, but freedom in being able to throw herself into her job without thinking of anyone else and the excitement of that. And the respect she’s getting from Strike because she’s good at what she does – I think it gets mixed up in her feelings for him.

The trip culminates in an overnight stay – and a very awkward conversation at the hotel reception over the number of rooms required. “Arriving at the front desk and not having had a conversation about whether or not they’re in one room or another and having the receptionist assuming that,” recalls Burke. “It floats the idea of them being in the same room.”

Blind spot

However, both Burke and Grainger are adamant that neither Strike nor Robin is aware of the “frisson” the viewer picks up on.

Burke: It's a blind spot and I think that is what is enjoyable about it. It is a really important quality of it.

Grainger: Any frisson that we pick up as viewers, I'm not sure that Strike and Robin are even aware of it themselves.

Could they live happily ever after?

On paper, Strike and Robin are chalk and cheese – but together they’re a professional dream team with countless fans hoping they get together for real. So… could there be a romantic union at some point?

There could be – but you could either go, 'OK, they’re completely in love and have been from the very first moment and it’s growing stronger every day and the best part of their day is each other and that’s their thing'. Or you could say they represent something in each other that is very much to do with who they are at their centre, and that doesn’t necessarily mean they’ll ever get together or if they should.

Grainger is also sitting on the fence…

They kind of fit together pretty well so far in every other aspect of their life. I can’t imagine them in a domestic setting, though. He might be quite difficult. It might be true love that breaks up over who does the washing up which would be pretty tragic and not great viewing.

Strike: Career of Evil starts on Sunday 25th February at 9pm on BBC1. Strike: The Silkworm is available to buy on DVD now.

Do you think Strike and Robin should get together?