I've mentioned before that Simon R. Green tends to go over the top more than an 80's era Sylvester Stallone action movie. However, with A Drood to a Kill, we're not nearly as silly as some of the other volumes in this series.
We start with Eddie Drood returning to Drood manor for a conversation with the new matriarch. Which involves breaking in, because of course it does. He's seeking information on why the family won't give him resources for figuring out what happened to his parents after the end of Casino Infernale. Long story short, he winds up getting suckered into going on a mission for the family to figure out why things are leaking out of a spy station run by the British government. This takes up most of the first half of the book, and includes Jack the Armourer giving Eddie the tricked out Bentley. That tends to take shortcuts through other dimensions.
Which leads, or course to meeting Uncle James' former Elven lover in the shifting lands. Who sends Eddie home without explanation, until he finds out the real reason, Uncle Jack died.
Which leads to a Drood funeral and a wake. From which Eddie's fiance, Molly Metcalf disappears. Which leads to a search to figure out where the Powers That Be took her to play The Game, wherein killing off the other contestants also gets rid of any infernal or divine contracts one may have pending on one's soul.
When Eddie finally makes it to the game, about three quarters of the way through the book, he not only finds Molly, but his parents.
It's quite a ride, and the plotting is extremely non-linear. Not to mention Green takes more than a few chances to tie in Deathstalker to the world shared by his other series.
However, there are a few themes crossing through this narrative that give it a bit more depth than normal. Among other things, after an encounter at the Department of the Uncanny, Eddie decides he doesn't want to kill anymore, regardless of who's asking him to. This gets explored quite fully during The Game. The other, as evidenced with the death of Jack and a few others, is that of old players leaving the spy game. It's actually kind of depressing.