The plot of Channel 5's new drama Intruder packs a number of intriguing mysteries, but the thing that will really have viewers scratching their heads is where on Earth it's supposed to be set.
One of the show's main characters, Rebecca (Elaine Cassidy), is a journalist working for a local newspaper called the Becksfield Gazette, which covers all the major goings on around a small seaside town.
However, husband Sam (Tom Meeten) is a presenter for a station called London Chat Radio, which means he must be tackling a hefty commute from this fictional shoreline to the centre of England's capital city.
But while it's unclear where exactly Becksfield is supposed to be on a map, we do know the real locations where Intruder was filmed – and it was an entirely different country all along.
Where is Channel 5's Intruder filmed?
Although Intruder is set in a small seaside town in England, the series was actually filmed in the Republic of Ireland, with much of the shoot taking place across the east coast in north Dublin and north Wicklow.
Some viewers may notice that the weather looks a tad gloomy in some of the outdoor scenes, but star Elaine Cassidy (who was born and raised nearby) explains that it was actually very reasonable by Irish standards.
"The weather was amazing," she told RadioTimes.com and other press. "I mean, this is Ireland. It rains all the time. We were there in October/November so we were really fortunate with the weather.
"There was nothing definitive about the time of year it is [in the script], but I don't think it was supposed to be the height of summer because we're wearing coats and stuff. So believe it or not, that was Ireland at its best."
But while the majority of filming unfolded in this area, the production did have to move elsewhere for the scenes involving an elaborate cave system.
We won't divulge any spoilers here, but a cave system connected to the Bexville Coast plays a significant role in the plot of Intruder and these scenes required the production to up sticks to Galway, towards the west of Ireland.
The entrance to the caves was filmed on Silver Strand beach, a location that co-star Sally Lindsay described as "magical", even when the weather conditions weren't quite ideal.
Cassidy's character, Rebecca, films several scenes inside the caves themselves and confessed it was a part of the shoot that she had been apprehensive about at first.
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"I was like ‘it's going to be freezing, it's going to be damp’, really not looking forward to it," she recalled. "And when we got there, there was another new energy.
"The caves were actually warmer than outside, we were so lucky because it pelted it down with rain but we were in this lovely little kind of safe cocoon. They were spectacular. We were even lucky enough to see some bats which felt really special."
Although notably, not everybody enjoyed spending time in the caves, as co-star Tom Meeten revealed that Intruder's writer-director was rather uncomfortable about filming these scenes.
"Gareth [Tunley], our director who wrote it, actually has quite bad claustrophobia. So, he was struggling inside the caves which I found quite amusing," he chuckled. "This is the sadistic side of me."
Intruder premieres on Channel 5 on Monday 5th April. Want more show content? Here is the full list of the Intruder cast. Take a look at the rest of our Drama coverage or visit our TV Guide to see what's on tonight.