Adding block_hook to my module causes ALL blocks to vanish...??

If I enable this function in my tapestries.module, all the blocks on my page just vanish. I stripped the function down to the point it does not actually DO anything, other than break the site. They still show up in the block configuration page, they just fail to display.

 /*
 * Implementation of hook_block().
 */
function tapestries_block($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    $blocks[0]['info'] = t('Tapestries MUCK character list and switcher');
    return $blocks;
  }
  else if ($op == 'view') {
    switch($delta) {
      case 0:
        $block['subject'] = t('Your Accounts');
        $block['content'] = 'Block content goes here...';
        break;
    }
    return $block;
  }
} 

What am I doing wrong here?