Congo is an interesting Micheal Crichton novel, though it has a very slow start from the prologue to them arriving in Zaire. Not just slow, but, boring slow. It's very much an infodump about the technology and history. There's far too much emphasis on the history of exploration of the area of Africa where they are, and it's hard to tell what's real from historical accounts and what was made up by Crichton for the plot.