The latest mystery thriller plunged retired detective Julien Baptiste (played by Tchéky Karyo) into a puzzling case about a missing girl called Natalie Rose.
Her uncle Edward Stratton (Tom Hollander) was wandering around Amsterdam desperate to find her, and his heartfelt plea tugged at Julien’s heartstrings.
But as viewers got to grips with the new pairing and watched as they began to bond over their shared experiences, producers pulled the rug out from under the entire show.
In the BBC episode’s final twist, it became clear Edward was not who he said he was.
And what’s more, Julien came face-to-face with Natalie Rose, only to discover the English man he’d already met wasn’t her uncle.
All was then unravelled when viewers spotted a smear of blood on the businessman’s sleeve.
Innocently eating a sandwich in his own home, Edward was plagued by flies, which immediately prompted confusion from viewers.
As they watched on in horror, the character went to his basement, where the camera panned across to show a dead man’s head wrapped in a cling film bag.
But why has the twisted Edward enlisted the help of Julien in his desperation to find Natalie Rose?
Does he have a grand plan to take down the detective?
The psychotic killer didn’t realise Edward would find his “niece” and begin to lift the lid on his lies, so the next twist could put a spanner in the works.
Luckily for Julien, he managed to get to the bottom of why Dragovic’s was helping the prostitutes.
Now his wife and family are in danger though, as a member of the Romanian gangs has been stalking her ever since he planted a listening device in her handbag.
Viewers flocked to Twitter to share their thoughts on the twist.
One person wrote: “Well I didn’t see that coming… #Baptiste.”
“OH S**T #Baptiste,” another fan said.
A third agreed: “ KNEW THERE WAS SOMETHING NOT RIGHT ABOUT HIM #Baptiste.”
While a fourth exclaimed: “I didn’t see it heading that way! #Baptiste.”
“B****y hell! #Baptiste,” a fifth added.
Baptiste continues Sundays at 9pm on BBC One.