As Nikki saved herself from certain death by clawing her way out of a coffin in the desert, viewers heaved a sigh of relief that the pathologist would live. 

The good news is that that hair-raising finale won’t be ignored as the 21st series of the long-running BBC1 drama begins, with Nikki still reeling from the effects of the trauma.

“She’s been buried alive – she’s not going to come out going, ‘Woo-hoo! That was great,’” quips Emilia, 43.

“It was a mega-episode and exciting, because it was putting Nikki in a place that we haven’t been before, so we couldn’t ignore that massive end. 

"It has continued into this series; we’ll see the after-effect on Nikki and on the relationships between the characters.”

We’re meeting Emilia, who started on the show back in 2004, on the set of Silent Witness, an unprepossessing office block in Acton, west London.

Also here today during a break from filming are Richard Lintern (who plays Thomas Chamberlain, the head of the centre), David Caves (Jack Hodgson), Liz Carr (Clarissa Mullery) and guest star Michael Landes. 

A new series of 10 episodes will see the team back tackling mysteries associated with the dead bodies – the silent witnesses – they examine in their morgue.

And although the series stretches the truth and has its pathologists rushing around doing detective work, this imaginative leap adds tension and complexity to the format.

It’s been a ratings hit since its debut in 1996, still pulling in more than six million viewers.  

“When you read about a crime in a newspaper, you want to know why it happened, who did it and how that crime is going to be solved, and Silent Witness deals with that,” says Emilia. 

As the series opens, we’ll discover that Nikki’s ordeal in Mexico has led her to reassess her life and priorities, which leads her to find love.

Michael Landes, who recently starred in Sky One’s drama Hooten & The Lady, guest stars as Matt Garcia, an American diplomat who captures Nikki’s heart when she attends a crime scene at the embassy.

Michael quips that their episode is “part crime drama and part Richard Curtis movie.” 

Emilia, laughs at this, and elaborates. “Nikki has not had a relationship for many, many years, which is often commented upon by fans,” says Emilia. 

“I was very concerned about Nikki being brought down by what happened in Mexico and wanted her to find a way to love life and appreciate life. Then… she meets someone and you actually see Nikki smiling!”

The 10-part drama, broken into five two-part films, covers myriad murders and disappearances.

There’s tragedy when a hospital database is hacked, which happened in the UK and elsewhere last year.

A US diplomat is shot dead in central London in another story, and the pathologists are called away from their Christmas dinners when they’re told about a shooting spree. 

It’s Emilia’s 13th series of Silent Witness after she took over from original star Amanda Burton in 2004.

“I still feel the same as the day that I started, and that is due to lots of factors,” she says. 

“I love the luxury as an actor of getting to play a character and getting to know her,” says Emilia. 

“I feel Nikki Alexander is very much part of my life.”