Derry Girls fans were left stunned on Tuesday night as the final season opened with a special guest star joining the shenanigans.

Warning: spoiler alert!

Writer-creator Lisa McGee had said that the episode, The Night Before, took "its tonal inspiration from Goodfellas".

But that was only half the story.

In one of the best-kept TV secrets of recent times, the cast and crew of the hit Channel 4 show managed to keep it under wraps that Liam Neeson had joined them - playing an RUC inspector.

With Erin (Saoirse-Monica Jackson), Orla (Louisa Harland), Clare (Nicola Coughlan), Michelle (Jamie-Lee O'Donnell), and James (Dylan Llewellyn) in custody, Neeson's character emerged from the shadows.

"Ok, ladies," he said, "I'd just like to ask you a few questions."

"Nice uniform," smiled Michelle approvingly.

"Thank you," said the man himself.

"Oh, you're welcome," said Michelle.

"Not now, Michelle!" said Jamie.

And the scene just kept getting better.

Derry Girls continues next Tuesday on Channel 4 at 9:15pm.

As to what's in store, McGee said: "In episode two, the family hire a hot plumber who everyone starts to believe Ma Mary's having an affair with. It's fun trying to work out what's actually happening.

"The gang are also going to perform in a Stars in Their Eyes concert at school for Children in Need and those two stories crash together."

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