They did a Q&A after with about half a dozen people, including the writer-director Rian Johnson (Star Wars VIII -- The Last Jedi and Looper). I stayed for about five minutes, but honestly I didn’t care what the editor or DP or composer and such had to say about making it. But he talked about his great love of mysteries and how he'd always wanted to make this for 10 years, but other films got in the way. He mention many films that were inspirations, but two singled out were Murder on the Orient Express and Sleuth,
Here's the trailer. It does a respectable job showing both the light-heartedness and tense mystery, though the movie is much breezier than the intensity this seems to build to and suggest.
By the way, the last two days I recorded talks shows to watch Jones and Redmayne talk about the movie. And I’m boggled that in neither case did they give them clips in the balloon to promote it. Redmayne at least had the presence of mind to say that the clip makes the movie look like a Victorian drawing room costume drama, and “It’s not that, it’s very adventurous.” So, if you've seen those appearance, don't be put off by the clips, which have little to do with the movie. And though you can see it on Amazon Prime, it's definitely recommended to see it in the theater. (Side note: when the film's producers signed their deal with Amazon Prime, it was not only set to get a theatrical run...but be shown on IMAX!! That's how important scope is to the film. But after signing the deal, Amazon pulled out of the theatrical business, and it will only be seen briefly in regular theaters. I'm sure the producers are crushed livid. As my friend wrote,"If crimes against art were prosecuted, they'd be on death row."
Here's the trailer. It's good and shows the film's craft wonderfully. Just know most of the movie is in the balloon, and this gives a sense that the bulk is earthbound.