Figure 4. We detect cosmic rays by counting stabilizer syndromes in spatiotemporal windows. Left: Each stabilizer produces a syndrome when its measured parity differs from the expected value. We can count the number of syndromes in a $w_s \times w_s \times w_t$ window, and trigger a ray detection event if this count exceeds some threshold. Right: When a detection event is triggered, we turn off all physical qubits within the offline flag radius $r_{\text{off}}$.