Behold the magic of pre_get_posts!

Add this to your functions.php file to change the main loop (in this example, it’s changing the taxonomy “series”):

add_filter('pre_get_posts', 'remove_series_pagination');
 
function remove_series_pagination($q) {
    if (is_tax('series')) {
      $q->set('posts_per_page', '-1');
      return $q;
    }
}