Any dogged detective knows that you need to do your research. Whether it’s poring over dusty files in a basement library or lurking around corners and dropping from eaves to listen in on whispered conversations, investigation is a crucial part of the job. And writer-director Rian Johnson has done his whodunit homework. Johnson gave the classic murder mystery a modern twist with 2019’s Knives Out, and now he’s back on the case with his Oscar-nominated Glass Onion screenplay. This time, world-famous detective Benoit Blanc (Daniel Craig) heads to Greece to keep a close eye on a tech billionaire and his eclectic crew of old friends. It’s very much in keeping with genre grande dame Agatha Christie’s Hercule Poirot novels — the familiarity of which provides the scaffolding to build a whole new story around.

“[The murder mystery] gives the audience some expectations and the appearance of a puzzle to solve,” Johnson tells Tudum. “You can take that and put it over other genres, and have a lot of fun and play with the form.” If you squint just a little you can see that Johnson has proven that he’s been a fan of whodunits his entire career. His terrific, kinetic debut Brick transposed the language and plotting of pulp icon Dashiell Hammett onto a California high school. Glass Onion cribs a bit from Christie’s Evil Under the Sun, as well as the Stephen Sondheim–penned pleasure-cruise thriller The Last of Sheila. But Johnson’s mystery passions hardly end there. We spoke to the Knives Out mastermind about his favorite Christie titles. Consider this a post–Glass Onion book club starter kit.

And Then There Were None
Christie’s bestselling mystery is And Then There Were None, a standalone thriller that Johnson describes as a proto-slasher. “It’s not a traditional whodunit, it’s not a Poirot or Miss Marple story,” Johnson says. In And Then There Were None, eight guests arrive on a small island, each having received a mysterious invitation. Soon, of course, people start to turn up dead. “It’s just this eerie, bizarre, scary, perfectly constructed little puzzle box of a horror story and I think it’s extraordinary,” he says.

The Murder of Roger Ackroyd
Another Christie novel, The Murder of Roger Ackroyd is famous for its radical twist, which takes a meta turn that some readers may not be expecting. So prepare for a little whiplash. “I think the audacity of the main twist is that it’s something that, if someone did it today, they would be accused of subverting the genre or worse,” Johnson says. “And I think it’s brilliant.” No spoilers here: You’ll have to read the book to find out.

Curtain: Poirot’s Last Case
In a series of switchbacks worthy of her own mysteries, Christie wrote Poirot’s final case in the mid-1940s, but authorized its publication only just before her death in 1976. The novel is an elegy of sorts for the famed Belgian sleuth, and another devilishly clever case from the “first lady of crime.” “It’s a fascinating solution to the mystery,” Johnson says, “and I think a very good example of how she was not afraid to throw out the rule book and to take wild, conceptual swings with the basic solution of these things. And it’s one that doesn’t get talked about a whole lot.”

Bonus lightning round! John Dixon Carr edition
Johnson also spotlighted one non-Christie fave: “I’ve been reading a lot of John Dickson Carr lately,” he says. “He’s an author who's a little less known than Christie, who I would encourage people to look up.” In particular, Johnson praises Carr’s amateur sleuth Gideon Fell, who was allegedly modeled on author G.K. Chesterton. “They’re much more mechanical than Agatha Christie’s books,” Johnson continues. “I think she’s much more character-focused and Carr is much more of the locked-door mystery, the puzzle box.” Where should a Carr neophyte start? “I would recommend The Mad Hatter Mystery. And also The Crooked Hinge. And I’ve also just read one called Hag's Nook that I thought was fantastic.” Time to hit the books!

Glass Onion: A Knives Out Mystery hits Netflix on Dec. 23.

Daniel Craig & Rian Johnson Discuss Glass Onion's Benoit BlancThere's no one better to explain than these two.