Block a single basic page from authenticated users
If you don't mind hard coding the node ID you could do this fairly easily in a custom module using hook_node_access():

function MYMODULE_node_access($node, $op, $account) {
  if ($node-&gt;nid == $node_id &amp;&amp; $op == 'view' &amp;&amp; $account-&gt;uid &gt; 0) {
    return NODE_ACCESS_DENY;
  }
  return NODE_ACCESS_IGNORE;
}