The series follows embassy chiefs as they fight to protect British nationals who find themselves in trouble in the Catalan city.
Mixing the roles of lawyer, counsellor and cop, their skills are stretched to the limit by a stream of challenging cases.
Here’s what you need to know.
Who stars in the new series?
Sophie Rundle (Gentleman Jack, Peaky Blinders) takes the lead as British diplomat Laura Simmonds.
Further cast joining the series include Danny Sapani (Killing Eve, MotherFatherSon) as Colin Sutherland, Steve Cree (A Discovery of Witches, Outlander) as Sam Henderson and Serena Manteghi (Mrs Wilson) as Alba Ortiz.
Isak Férriz (Libertad, Giants) joins as Inspector Castells and Laia Costa (Soulmates, Devils) as Mariana Cabell.
What’s it about?
The Diplomat follows Laura Simmonds (Sophie Rundle), a British consul in Barcelona who is forced to become a de facto cop, counsellor and lawyer as she helps holidaymakers out of a variety of scrapes.
The series opens with the unexplained death of a young British barman working on a yacht in Barcelona’s notorious marina.
While the Spanish police believe that the death was a tragic accident, Laura supports the boy’s grieving father, Colin (Sapani) who is convinced something more sinister took place that night.
As new evidence emerges and a murder enquiry is opened, Laura and Alba find links between the barman’s death, organised crime and the British security services.
Laura’s quest for justice places her in real jeopardy, as she threatens to expose secrets that the British and Spanish will go to any lengths to keep hidden.
Speaking to i, Sophie Rundle said: “One of the things I really liked about Laura is her competence,” says Rundle.
“She’s not there because of privilege. She’s not there because of nepotism. She’s worked her way up. It’s really satisfying to see that in a protagonist – that she’s not an anomaly as a woman in this high-up position.
“It’s like, ‘Yeah, too f***ing right she is’.”
What time is it on?
The Diplomat airs on Alibi from 9pm on Tuesday 28 February. The following five hour-long episodes will be shown in the same slot.