"Legend of the Sea Devils" is the second and penultimate of three special episodes that followed the thirteenth series of the British science fiction television programme Doctor Who.

In the episode, the Thirteenth Doctor (Jodie Whittaker) and her two companions, Yasmin Khan (Mandip Gill) and Dan Lewis (John Bishop), set out to find the hidden treasure of the Flor de la Mar.

However, they end up in the wrong time period and team up with Madam Ching (guest star Crystal Yu) as they battle the Sea Devils for an important gem.

In 1807 China, the pirate Madam Ching raids a village and, using a gem, unwittingly releases the Sea Devil Marsissus from a stone statue.

The Doctor and Yaz take the TARDIS back 274 years and witness a Sea Devil betraying Ji-Hun aboard the latter's ship.

Marsissus seizes the Keystone from Ying Ki just as the Doctor realises the Sea Devils plan to use it to flood Earth.

Madam Ching announces she has recovered enough treasure to pay the ransom and will make Ying Ki a member of her crew.

[7] One of Road's contributions was the addition of the historical figure Zheng Yi Sao, also known as Madam Ching, to the special.

[8][9] Also depicted is the Flor de la Mar, a sailing ship that sunk off the coast of Indonesia with stolen goods that were never recovered.

"[14] As part of the promotion for the episode, Scottish musician Nathan Evans released a Doctor Who-themed adaptation of the sea ballad "Wellerman".

Mandip Gill and John Bishop portrayed the Doctor's companions, Yasmin Khan and Dan Lewis, respectively.

Crystal Yu was cast to play Madame Ching while Arthur Lee and Marlowe Chan-Reeves guest starred as Ji-Hun and Ying Ki.

[22] The updated designs for the Sea Devils were created by costumers Ray Holman and Maker Robert Allsop.

[23] The Sea Devils were made shorter than they were in previous episodes to compensate for the height difference between Whittaker and Third Doctor portrayer Jon Pertwee.

[39] On 18 November 2022, composer Segun Akinola announced that selected pieces of the score from this special would be digitally released on 9 December 2022.

[26] Benji Wilson, writing in The Daily Telegraph, said that his kids thought the Sea Devils were "cute", which undermined the perceived scariness of the episode.

However, he praised the "nascent queer relationship between the Doctor and Yaz", commenting that the interplay between the two characters was "genuinely affecting".

[44] Awarding it three stars out of five, Martin Belam of The Guardian said the episode "promised a swashbuckling Easter special, and it partially delivered", but he felt that the scenes between the Doctor and Yaz towards the end "didn't necessarily ring true".