Meteor: Get cached minimongo results from API

Question

I am retrieving a list of users from a 3rd party API which is working pretty well. However, when I click to view the details of a user I would like to use the result from the cached collection (minimongo) of users if available otherwise I would make another API call to retrieve the data.

However, there's something a bit odd going on the the user details route. If I log the results of User.findOne(this.params._id), I see the User object logged, then I see "undefined" logged.

Is this even possible, or do I need to make an API call every time a visitor views the user details page?

Routes:

Router.route('/users', {
    name: 'usersList',
    waitOn: function() {
        Meteor.subscribe('usersGet');
    }
});
Router.route('/users/:_id', {
    name: 'userPage',
    data: function() {
        var user = Users.findOne(this.params._id);
        // Logic to determine if user is found or a call to the API is required
        // Logging the results to the console initially displays the user object, but then displays undefined
        return user;
    }
});

Collection:

// lib/collections/users.js
Users = new Mongo.Collection('users');

// server/users.js
Meteor.publish('usersGet', function () {
    var self = this;

    try {
        var response = HTTP.call("GET", "http://api.com/users", {
            headers: {
                // headers...
            }
        });

        _.each(response.data.users, function (user) {
            self.added('users', user.id, user);
        });

        self.ready();
    } catch(e) {
        // handle errors
    }
});

User Page: (I also attempted to create a helper, but I got the same results)

Template.userPage.helpers({
    user: function() {
        var user = Users.findOne(this._id);
        console.log(user); // I initially see the user object the server retrieved earlier logged 3 times, but then it logs "undefined"
    }
});