Michael Crichton - Congo

If you saw the 1995 film adaptation of this Crichton thriller, somebody owes you an apology. While you're waiting for that to happen, try reading the vastly more intelligent novel on which the movie was based. The broad lines of the plot remain the same: A research team deep in the jungle disappears after a mysterious and grisly gorilla attack. A subsequent team, including a sign-language-speaking simian named Amy, follows the original team's tracks only to be subjected to more mysterious and grisly gorilla attacks. If you can look past the breathless treatment of '80s technology, like voice-recognition software and 256K RAM modules (the book was written in 1980), you'll find the same smart use of science and edge-of-your-seat suspense shared by Crichton's other work.

Michael Crichton - Andromeda Strain

The United States government is given a warning by the pre-eminent biophysicists in the country: current sterilization procedures applied to returning space probes may be inadequate to guarantee uncontaminated re-entry to the atmosphere. Two years later, seventeen satellites are sent into the outer fringes of space to "collect organisms and dust for study." One of them falls to earth, landing in a desolate area of Arizona.
Twelve miles from the landing site, in the town of Piedmont, a shocking discovery is made: the streets are littered with the dead bodies of the town's inhabitants, as if they dropped dead in their tracks.