I'm not that up-to-date with the various character arcs, but that didn't feel overly necessary (though what's happened to Dwayne! 😲). The slightly spooky mystery was a good one, which managed to play both the twins card and the multiple personality card without making either the final big twist, which is better than other, much higher budget recent murder mysteries managed (*cough* Glass Onion *cough*). Plus, they managed to weave the supernatural elements into the plot in a way that made it genuinely creepy whilst also explaining them all fully, whilst also providing several moments of character development, and you can't really ask for much more than that from a lighthearted TV serial.