Sitting down to watchEastEnders' ambitious new spinoff dramaKat and Alfie: Redwater, you could be forgiven for having pretty low expectations.

First and foremost, soap spinoffs usually suck and bring back memories of straight-to-videoEmmerdalespecials likeDingles Down Under. In this case, we've also waited a whopping two years forRedwaterto hit our screens afterthe much-hyped initial announcement, testing our patience just a tad.

Some weird BBC decisions haven't inspired much confidence, either. BBC One has opted not to show the series on the same day as Ireland, meaning thatspoiler-hungry fans are reading about all the biggest twists online four days before they actually get to see them on screen. Surely for a series that's being compared to event TV likeBroadchurch by its own producers, a joint airdate for maximum impact makes more sense?

Beeb bosses have also raised a few chuckles among fans by tacking "Kat and Alfie" onto the show's title for UK viewers at the eleventh hour, a climbdown from previous attempts to completely distanceRedwater from theEastEnders brand.

Enough griping, though – as any early alarm bells have well and truly been silenced with an impressive and atmospheric first episode proving that ourRedwater reservations may well have been unfounded.

The Moons' new adventure sees them arrive in a beautiful Irish harbour village on the search for Kat's long-lost son, picking up onanEastEnders storyline which began way back in May 2015.

Kat and Alfie have a secret plan as they turn up in Redwater – play the long game, make friends, fit in and don't ask too many questions straight away.

Of course, subtlety isn't Kat Moon's strongest quality and it's not long before she's decided the first dark-haired 30-something guy she sees must be her offspring – infuriating Alfie and arousing the suspicions of local matriarch Agnes Byrne in the process.

Kat spends most of episode one fixated on the idea that local man Andrew Kelly (Peter Campion) is her son and it's these scenes which stand out as some of the show's strongest, finally bringing back the vulnerability and warmth to Kat that was often missing inEastEnders during Jessie Wallace's second stint in the role.

But as Kat herself points out, she was never really going to find her long-lost son in the first 10 minutes (not with six hour-long episodes to fill) and as the first slice ofRedwater drama progresses, we discover that she's most definitely on the wrong track with this one.

As the steely Agnes and her husband Lance are well aware, Kat's son is actually the local priest and perceived pillar of the community, Father Dermott Dolan.

Aside from a mysterious and unexplained hatred of orange juice, Dermott seems normal enough – devoted to helping the locals, making the odd joke here and there, and even rescuing Alfie from the brink of death when he finds himself in danger on a cliff. (Saving the BBC the effort of changing the title toKat: Redwater.)

But just when we're twiddling our thumbs wondering how long it'll be before Father Dermott moves to Walford with Kat and spends his days listening to sins inEastEnders,Redwater finally pulls the rug from under us with a truly shocking twist.

After Dermott learns his true parentage from an indiscreet Lance, the man of God suddenly turns murderous and brutally drowns him in the sea. And it turns out it's not the first time he's struck, with dark flashbacks showing how he dished out the same treatment to his adopted mum when he was just a boy in 1994.

In truth, we'd often wondered whetherRedwaterwould just be a long-winded precursor to Kat's son becoming anEastEndersregular and refreshing the Moon family, but now all bets are off and the stage looks set for what's sure to be one hell of a ride over the next five episodes.

Will the devilish Dermott strike again? Is Kat in danger? And how many more secrets does the fearsome Agnes hold the key to?

Of course, as with any new show, some aspects are working better than others at this early stage. While Kat shines inRedwater, it's fair to say that Alfie seems a little bit lost and directionless in the first episode, with even scenes of him experiencing weird visions and nearly dying (twice!) seeming like time-fillers.

It'll also take some time to properly get to know the new characters, although Agnes and Dermott – played by the excellently eerie Fionnula Flanagan and Oisin Stack – have immediately caught our attention.

The jury's also still out on just how much appealRedwater will have to a non-soaps audience. Even with the stunning Irish scenery and impressive cast, surely you have to be anEastEnders watcher to really care about Kat's quest for her son?

As huge soap fans, though, for us it's a thumbs up ifRedwater can keep up the suspense, surprises, gothic tone and sense of foreboding that sets it apart fromEastEnders. It would also be fantastic if it could pave the way for more big-budget soap spinoffs,asEmmerdale producer Iain MacLeod hinted recently.

And who knows – withEastEnders itself currently slightly lacking in engaging long-term story arcs, maybe it'll beRedwater which gives us our much-needed dose of gripping soapy drama over the next few weeks. Perhaps they could even ship Dermott over to Walford after all to liven things up...

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