The Black Hole War
It is well known that General Relativity and Quantum Theory don't get along very well. GR predicts black holes which can swallow anything, including information. Quantum theory says that information cannot be destroyed, only transformed. Hawking took the first point of view, Susskind the second, and this book describes some of the ingenious arguments he used to prove his point.
The book starts with an explanation of black holes and quantum theory and moves on to Susskind's explanation of his ideas, which do seem rather bizarre. The event horizon of a black hole acts as a hologram, giving a 2D representation of the3D interior of the black hole, so objects can seem to disappear at the singularity while their information is preserved at the horizon, later to be emitted as Hawking radiation. It's advanced stuff, but Susskind is very skillful in making it accessible to a wide readership using a minimum of technicalities and plenty of autobiographical material, such as the question of whether an American professor is allowed to walk on Cambridge lawns. Highly recommended.