Return statement in promises

I'm writing a simple controller for a GET request in node.js that uses promises. The code works, but I'm not 100% sure why. I have a getStoriesHelper function that returns a promise, and after I get the result, it does return res.json(listOfStories);. This works, but I was under the impression that returns only breaks out of a single function scope (so I assume it should only break out of the anonymous function scope), and just wondering why it would break out of the getStories function as well?

//for instance, the return statement only breaks out of the anonymous function and not from dummy()
function dummy() {
    _.map([1, 2, 3], function(element) {
        return element * 2;
    }
}

//node.js controller
exports.getStories = function(req, res) {
  var studentId = req.params.studentId;

  User.findOne({role: 'student', _id: studentId}).exec()
    .then(function(student) {
      var isNursery = student.status === 'attending class' && user.bookLevel === 'nursery';

      getStoriesHelper(student, isNursery).then(function(listOfStories) {
        //shouldn't return only break out of this inner function scope
        return res.json(listOfStories)
      });
    });
};

//dummy async code
function getStoriesHelper() {
  var deferred = Q.defer();
  setTimeout(function() {
    deferred.resolve(123)
  }, 3000);
  return deferred.promise;
}