The left string, after completing the second outermost main string, exits from top-left hole 10 and pauses.
After all main strings are completed, the right string enters upward at bottom-right hole 13, completes one cross string, then enters downward at bottom-left hole 12, and continues upward to complete the outermost left main string.
The right string then moves down by one hole, enters top-left hole 13 to become a cross-string path, and continues downward to complete the lower cross strings.
The left string then resumes from the paused position, skips downward by 1 hole, enters top-left hole 12, and completes the upper cross strings.
Pattern Notes