The path-integral approach to topological quantum error correction provides a unified way to construct and analyze fault-tolerant circuits in spacetime. In this work, we demonstrate its utility and versatility at hand of a simple example: We construct a new fault-tolerant circuit for the toric-code phase by traversing its path integral on a ((x,y,z)) cubic lattice in the (x+y) direction. The circuit acts on qubits on a square lattice, and alternates between horizontal nearest-neighbor (CX) gates and vertical nearest-neighbor (ZZ) and (XX) measurements. We show how to incorporate boundaries and corners into the fault-tolerant circuit and how to perform topologically protected logic gates. As a specific example, we consider performing a fault-tolerant logical (ZZ) measurement via lattice surgery of two spatial rectangular blocks of our fault-tolerant circuit.