The Domino Pattern by Timothy Zahn stuck out to me because the cover was pretty, I liked the font, and I knew I recognized the author's name, although I was pretty sure I'd never read any of his books. Star Wars fans will recognize his name because of his many books about Admiral Thrawn and Han Solo. Domino Pattern features Frank Compton, a loner detective, on a train, solving a murder. Sounds pretty Agatha Christie (re: the train) or Dashell Hammet (re: loner detective), right? Well you would be right, except the people murdered are aliens, and the train is a sort of supergalactic highway across space run by a species of spiders. I really enjoyed the melding of the traditional "must solve the mystery before the end of the train ride" and the mixing of alien cultures, including an alien/human hybrid "Girl Friday" for Compton. Compton was once a cop for Westali, which would be the European Union for us, but was blacklisted due to irritating his superiors by uncovering a plot funneling money to another world. Unfortunately for him, his superiors were the ones doing the money laundering and the cover up.
About halfway through the book I realized that yes, once again I had picked up a book that was the fourth in the series of books that started out back in 2005 with Night Train to Rigel. I went ahead and went back and read the first three including The Third Lynx and Odd Girl Out (I'm in the middle of it right now). Even though the whole series has a futuristic bent, my favorite part by far is the humanity of the characters amidst the strange backdrop. In fact one of his publishers, Random House, has a blurb for him that sums this up, that he is "known for pitting realistic human characters against a well-researched background of future science and technology." Each of the books has a murder at the center of it, while intergalactic politics and intrigue are scattered throughout, making these some of the most enjoyable books I've read in awhile.