The Havana Room by Colin Harrison

It's a thriller, and I enjoyed it! I think that's only ever happened once
before! It's the story of a Manhattan lawyer whose whole life falls apart
around him, and then gets entangled in what at first looks like a simple
real estate transaction, but turns out to be a complicated mess that I'm not
going to describe further because it would spoil the book. Despite the fact
that it's a thriller, there's a mystery element, so the reader can try to
put the pieces together before the protagonist does. The plot dances on the
border of cliche, but every time it looks like it's going to cross that
line, some unexpected element (fish? WTF?) is thrown in there to make
things more interesting. By the time I was 150 pages from the end I
literally could not put it down - I had to stay up an hour or two past my
bedtime to finish it!