The Bay star bawled her eyes out over emotional season 5 story

Best is known for roles in Ripper Street, Four Lives, The Walk-In and Cold Feet so is certainly a familiar face in the world of TV drama. But Thomason says that it is in her role as grieving mother Julie Ashworth that Best delivers quite the performance.

Speaking to RadioTimes.com and other press in a press conference for the new series, Thomason said of balancing harrowing storylines: “It’s wonderful, I love playing Jenn and she’s a lot to sink my teeth into. I’m really grateful for that.

"One of the scenes that comes to mind is when Jenn goes to tell Julie, played by Leanne, that her daughter is dead. We rehearsed it.

"I mean, Leanne is incredible in this series, an incredible actor. But my gosh, in this rehearsal, it was unbelievable. I couldn’t hold it together, I was just bawling my eyes out."

She added: "I could not be a family liaison officer. It was so incredibly moving, she just was right there and every take. That was just the rehearsal … just incredible.

"It’s just such a privilege to be able to tell these stories. People go through this stuff in real life, people really go through these kinds of horrors. I enjoy the challenge, I enjoy the emotion of it all. I have a really fun time and I’m completely drained."

The new series centres on the death of university student and Julie's daughter Hannah, who is found on the edge of the docks and who Jenn has to inform in the new season's first episode.

Speaking to the grief that underpins this season, as well as Best's performance, writer Daragh Carville said in a press pack for the season: "There is a darkness at the heart of this show, given what we're dealing with. We're exploring the impact of loss, the impact of grief, but I hope it's not just unremittingly grim, because it's also about finding a way through grief and coming out the other end.

"But when you're dealing with murder and when you're dealing with what that does to a family and to a community, you have to be prepared to look that in the face and really explore truthfully, what that feels like.

"The added element this year is Leanne Best's performance and the rawness of emotion that she was able to access in a way that I'm not sure we've quite done before. But there's always light as well as darkness in the show, we don't just focus on the dark side, there's also joy and humour in there."

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As we also come to see this season, Jenn (Thomason) is processing her own grief as she recently lost her father. However, she thinks this new case is an opportune time to return to work.

The official synopsis states: "With the stakes of the investigation high, Jenn and the team dig deeper into the case, uncovering hidden friendships and secret liaisons as anger rises in the student community.

"As the intensity increases and the team peel back the complicated layers of Hannah’s life and the secrets within it, Jenn must reconcile her personal and professional struggles as she grapples to solve the case, come to terms with her own loss, and build bridges with her family."

As well as Best in the guest cast, other additions also include Neil Maskell (Hijack, Kill List), David Troughton (A Very Peculiar Practice, New Tricks), Stephen Wight (Screw, I May Destroy You) and Ceallach Spellman (Better, White Lines).

The Bay will return to ITV1 and ITVX on Sunday 2nd March at 9pm.

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