There is no such thing as a simple miracle.

Dr. Malcolm Sayer, a shy research physician, uses an experimental drug to "awaken" the catatonic victims of a rare disease. Leonard is the first patient to receive the controversial treatment. His awakening, filled with awe and enthusiasm, proves a rebirth for Sayer too, as the exuberant patient reveals life's simple but unutterably sweet pleasures to the introverted doctor.