MongooseJS and the problem with adding new properties

My setup is easy. Node.js, ExpressJS, MongooseJS. The Problem I was getting a list of objects from the MongoDB. Like this // Find all items where owner in following array Thing.find().where('owner').in(following).populate('owner').populate('comments.userId').sort('-updatedOn').limit(20).exec(callback); In the callback I was assigning the results to res.locals.things for use in another middleware function. In another middleware function I tried this // Extend thing[i] with a new property called newProperty forvari=0;i<res.locals.things.length;i++){res.locals.things[i].newProperty='hello';} When I would echo out my things, newProperty was not in there.