title: How to break promise chain in Mongoose
body: <p>I'm migrating my Mongoose code to use Promises to avoid The Pyramid of Doom.
  I want to break the Promise's chain on a certain point, but I don't know how to do it.
  Here's my code:</p>
  
  <pre><code>var data = {};
  
  People.find({}).exec()
  .then(function(people) {
  
      if (people.length == 0){
          // I want to break the chain here, but the console.log() gets executed
          res.send('No people');
          return;
      }
  
      data['people'] = people;
  
      return Events.find({
          'city': new mongoose.Types.ObjectId(cityID)
      }).lean().exec();
  
  }).then(function(events) {
      console.log('here');
      data['events'] = events;
  
      res.send(data);
  });
  </code></pre>