I've spoken before about some of my biases when it comes to storytelling. For instance, I'm overly fond of stories about sentient books, not a big fan of metaphorical "they're all really dead" stories. I think I'm neutral when it comes to the noir-ish private investigator trope which shows up so often. However, I am decidedly a fan of well-done closed-door mysteries. I'm not a regular murder mystery reader, but Murder on the Orient Express is one of my all-time favorite books.
So as "Not Even the Past" moves from well-realized diplomatic tale on a space elevator to closed-room murder, I was delighted. It starts out with a great hard-sf hook: cooking on a space elevator. You thought cooking on a sail boat might be hard! This chef's got problems that have barely been dreamed of so far. Plus, given the nature of the story, he has to cook individual meals of completely different ethnic cuisines to cater to the various diplomats on board. He's got pressure cookers, LED indicators, and everything has to be stowed and accounted for so as not to go astray in the ever-changing gravity.
This makes it easy for the chef to notice when there's a knife missing after dinner, but before he can do anything about it, the unpleasant Chinese ambassador has been murdered. Now we find out that the chef isn't merely a chef, he's also security personnel, and it's his job to try to solve the mystery.
Which he does. The story eventually covers a lot of ground, including the national and personal sins of the past coming back to haunt the victim. It makes a very good point about Chinese relations with the world, although we shouldn't assume that China is the only bad actor on the national stage. Nations, and powerful individuals, do a lot of very nasty things. Sometimes, at least in small ways, the little people take revenge.
This is a well-paced, serious story, with good hard-sf furniture, and a little more political nuance than average. It doesn't take itself too seriously, even when dealing with serious issues, which also helps. It stays a story, without becoming too much of a lecture.