#Creepy brothers at center of twisty thriller ‘The Bad Seed’

“The Bad Seed” does family dysfunction like nobody’s business.

This five-episode New Zealand crime thriller, based on Charlotte Grimshaw’s novels “The Night Book” and “Soon,” arrives Thursday (April 29) on Sundance Now. It’s a binge-worthy murder mystery packed with twists and turns that will keep you guessing from beginning to end (and then some).

While it does recycle some familiar murder-mystery tropes — i.e. the suave, successful husband hiding dark secrets from his wife — there’s much more to “The Bad Seed” than first meets the eye.

Dr. Simon Lampton (Matt Minto), seems to have it all: he’s a successful obstetrician living in a swank Auckland suburb with his loving, civic-minded wife, Karen (Jodie Hillock) and teenage daughters Claire (Zoe Jansson-Bush) and Elke (Madeleine McCarthy). Simon’s older brother, Ford (Dean O’Gorman), who’s “between girlfriends,” is living, for now with the Lamptons. He runs a landscaping business and helps look after his nieces.

The murder of the Lamptons’ neighbor, Julia Stevens — knifed-to-death in her kitchen — opens the Pandora’s Box from which the rest of series flows. Simon, it seems, not only had a history with Julia, but he’s also got a mistress, Mereana (Keporah Torrance), a waitress who lives on the other side of the tracks.

Karen, meanwhile, is working hard to elect David Hallwright (Xavier Horan) as New Zealand’s next prime minister. He’s young, charismatic and leads in the polls, but his wife, Roza (Chelsie Preston Crawford), has a checkered past and is the subject of internet trolls criticizing her lavish lifestyle. She takes a liking to Simon and Karen, enthusiastic contributors to her husband’s campaign coffers … and to Elke.

On the surface, Mereana and the Hallwrights appear to be disparate characters. They’re not. Thrown into the mix is Det. Marie Da Silva (Madeleine Sami), who’s working the Stevens murder and suspects Simon’s involvement.

And then there’s Ford, with whom Simon shares his secrets. Ford supports his kid brother, maybe a little too much, but it’s the result of their screwed up childhood. Their drug-addicted mother died when they were young, leaving them to be raised by their cruel, sadistic father, Frank (Danny Mulheron), who lives on a cluttered, dilapidated spread dotted with junk and skinned rabbits. His presence hovers over his sons like a toxic cloud.

That’s all you need to know about “The Bad Seed” because it gets even more complicated and I don’t want to spoil anything. Half the fun is watching each episode to see what shocker is just around the corner as Simon, Ford, et al. get swept up in a story that careens around each curve like a runaway train.

The series premiered in 2019 to positive critical reaction in New Zealand, and I’ll echo those sentiments: it’s a sharply written, deftly acted, edge-of-your seat thriller from its opening season straight through to its finale.