The War Between the Land and the Sea spoilers won’t be found in this review.

Doctor Who spin-off The War Between the Land and the Sea certainly knows how to grab your attention. In the premiere’s cold open, hapless fishermen accidentally pull an aquatic monster out of the icy ocean depths. But things then warm up quickly after we’re suddenly thrown into bed with a shirtless Russell Tovey.

Doctor Who maestro Russell T Davies certainly knows what fans like to see, although this UNIT spin-off might surprise you with the noticeable lack of a certain Doctor.

Instead, this five-episode limited series revolves around Barclay, Tovey’s low-level UNIT employee, who suddenly finds himself promoted to a job he never wanted.

Due to a perfect storm of circumstances, Barclay ends up becoming humanity’s ambassador to the Sea Devils, now known as Homo Aqua, when they rise up out of the ocean and demand retribution for… well, everything. And rightly so. The people of Earth have been destroying their home for decades, and Homo Aqua were actually here first.

Barclay is out of his depth, of course (pun absolutely intended). This is a crisis of global proportions, and with no Doctor in sight, it’s up to the world’s governments and some familiar faces at UNIT to find a way out of this calamity.

Chief among them is Jemma Redgrave as UNIT’s head honcho, Kate Lethbridge-Stewart. Recent seasons of Doctor Who have given Kate more opportunity to shine as a character in her own right, but not as much as this new spin-off does. Romance is even in the wings, although there’s not a lot of time for anything too personal with so much at stake.

That’s especially true of side-characters like Ruth Madeley’s Shirley (at least, in the two episodes we were given access to ahead of the show’s launch). It would have been nice to see more of UNIT members like her in a UNIT-based spin-off such as this, but most of the show’s runtime is instead dedicated to Barclay and Gugu Mbatha-Raw’s new character Salt.

Tovey’s everyman brings in moments of humour as the sheer scale of what’s happening threatens to overwhelm him. He also grounds what could have come across as a rather silly infatuation with Salt, although Barclay isn’t particularly interesting as a lead. He’s supposed to be a little bit boring, of course. That’s the whole point. The problem is Tovey pulls this off a little too well.

Barclay’s family come across even more stilted, and that’s true of almost everyone here outside of the core UNIT lineup. You get that sometimes with bit players in Doctor Who, but there’s no excuse when it comes to a limited series like this where these characters inevitably play a bigger role.

The exception, however, is Loki star Mbatha-Raw. Her career comes full circle with this performance following a very early role of hers in Doctor Who where she played Tish Jones, sister to Martha Jones. Salt is very different to Tish, and not just because she breathes through gills.

While the rest of the cast fail to live up to the epic quality of storytelling here, Mbatha-Raw brings some much-needed gravitas as the leader of Homo Aqua. It’s in her initial meeting with humanity, and Barclay especially, where the potential of The War Between Land and Sea really begins to flow.

What could have been a preachy treatise on the impact of climate change feels far blunter and therefore more impactful coming out of Salt’s mouth. It’s not as smart perhaps as other Davies’ projects like Years and Years, but maybe it’s better to avoid subtlety with a project directed at a demographic as wide as this one.

Words alone aren’t enough. The actions taken by Homo Aqua also feel rather larger than life, establishing this as a global conflict through the use of various landmarks that remind us that this show is indeed set in the wider Whoniverse. Some sets from Torchwood‘s third season, Children of Earth, are even reused, plus Colin McFarlane returns again in the same role of General Austin Pierce.

Deliberately evoking such comparisons does The War Between Land and Sea no favours though. While the parallels between these two projects are clear, Doctor Who‘s latest spin-off lacks the spark that Torchwood brought to the Whoniverse. The result is ambitious yet awkward, as endearing as it is clunky.

Still, there’s certainly some fun to be had with what can only be described as The Diplomat meets The Abyss via Doctor Who on Valentine’s Day.

And even if it is flawed, a UNIT spin-off that treats UNIT seriously has long been overdue, suggesting that there’s scope for plenty more stories in this vein. Let’s just make Jemma Redgrave the lead next time though.