It might look something like this:
PagesController.show = function() {
var self = this;
var page = this.param('page');
if (page !== undefined) {
page = page.replace('.html', '');
this.render("./" + page, function(err, html) {
if (! err)
return self.res.send(html);
self.redirect({ action : '404' });
});
} else {
// this will probably never be called, because `page`
// won't be undefined, but still...
this.redirect({ action : '404' });
}
};