The Crying of Lot 49 - Thomas Pynchon

I have read one book by Thomas Pynchon, this one. I won't read another one for a while. There must be some meaning in the story, further than the one that's plainly told. I wonder which might it be. Here we are in the sixties (so far away now) and Oedipa Maas gets involved in an elusive plot about an alternative postal mail distribution company operating since the eighteenth century. Postmodern fiction, they insist.