Acclaimed actress Gugu Mbatha-Raw has described the experience of transforming into a completely unrecognisable amphibian for a new Doctor Who spin-off as a uniquely 'liberating' challenge. The star, a familiar face in the Whoniverse, undergoes a radical metamorphosis for her lead role in 'The War Between the Land and the Sea'.
A Radical Transformation Behind the Prosthetics
Fans may best remember Mbatha-Raw as Tish, the sister of former companion Martha Jones. However, in this new series, she is hidden behind three hours of intricate makeup and prosthetics to become Salt, the leader of the Homo Aqua species. Salt serves as a love interest for the human co-lead Barclay, played by Russell Tovey.
Speaking at the series premiere, the actor detailed the extensive process, involving 'many, many fittings' and 'many, many makeup tests'. She revealed the unexpected freedom it provided. 'Just [through] the physicality of the prosthetics, I found the final results quite liberating as an actor because you weren't able to rely on your usual image or look, and people were looking at you differently,' Mbatha-Raw told Metro. 'I think that is really exciting.'
She praised the role as 'extraordinary', noting, 'you don't get offered to play an amphibian every day. I was curious how and if I could play this character. It was a totally unique challenge, completely different to everything I've ever done.'
Finding Humanity in an 'Othered' Character
For Mbatha-Raw, the role extended far beyond the physical transformation. She delved into the complex emotional journey of Salt, a character who is 'really steely, regal and defensive' but who also discovers a childlike capacity for love.
'[It was about] just find[ing] the humanity in a character who has been othered and ostracised by the human race,' she explained. 'There was a lot there.'
Her performance left a profound impact on her co-star and the production team. Russell Tovey recounted the moment she first appeared on set as Salt. 'A 'silence' swept through the entire cast and crew the first time Mbatha-Raw disappeared and Salt took her place,' he said.
Addressing Mbatha-Raw directly, Tovey continued: 'It was just magical, and you held that space, and you had such poise and finesse and elegance. Everyone was just in awe of you every day. I get emotional talking about it.' He expressed amazement at her dedication, noting she endured three-and-a-half hours in makeup before filming even began.
A Five-Episode Event with a 'Definite Ending'
The series, created by Russell T Davies, has been confirmed as a five-episode limited series with a 'very, very definite ending'. Davies has encouraged viewers to stay until the very end for 'one of the most beautiful scenes ever recorded'.
In a four-star review for Metro, Senior TV Reporter Asyia Iftikhar suggested the series meets the high standard of Davies's past work, such as 'It's A Sin'. The review praised both leads, stating that 'the latter especially wows as Salt, given the nuance that comes with portraying a non-human character.'
As for returning to their previous Doctor Who roles, Tovey adopted a 'never say never' approach but emphasised their current focus. 'I think we're so invested in Barclay and Salt right now, they're really occupying us. We really want people to connect with them... They're brand new characters for people to connect to.'
'The War Between the Land and the Sea' premiered with its first two episodes on BBC One at 8:30pm on Sunday, December 7, 2025.
