The third of the five movements that comprise Gyorgy Ligeti's (1968) Second String Quartet bears the performance instruction "come un meccanismo di precisione," or "like a precision mechanism." More than just a performance instruction, these words describe the image that the music conjures, as well as the composition itself. This paper is an analytical presentation of the movement which highlights Ligeti's use of golden section proportions, symmetry, numerical series, and permutation.