On one hand, The Order was a six-issue limited series featuring the Defenders. On the other hand, The Order was a continuation of Defenders (Volume 2), which ran for 12 issues.
Through a creative use of cover numbering, The Order #1 combined both perspectives and displayed 1 with 13 nested inside.
Likewise, The Order #2 displayed 2 with 14 nested inside. The pattern continued through the duration of the series, with The Order #6 displaying 6 with 18 inside.