 
       # Ignore the spine because it is defined by the navTree in EPUB3.
       # **TODO:** Fall back on `toc.ncx` and then the `spine` to create a navTree if one does not exist
-      return {
+      return $.extend {
         title: title
         bookId: bookId
-      }
+      }, metadata
 
     serialize: () ->
       serializer.serializeToString(@$xml[0])

define [
  'backbone'
  'cs!collections/media-types'
  'cs!collections/content'
  'cs!mixins/loadable'

        )
          
      @on 'change:language', (model, value, options) =>
        tagHelper('dc:language', value, {'xsi:type': "dcterms:RFC4646"}) unless options.parse
      @on 'change:description', (model, value, options) =>
        tagHelper('dc:description', value) unless options.parse
      @on 'change:rights', (model, value, options) =>
        tagHelper('dc:rights', value) unless options.parse

      metaHelper = (value, attributes) =>
        tagHelper('meta', value, attributes)

      @on 'change:rightsUrl', (model, value, options) =>
        metaHelper(value, {property: "lrmi:useRightsUrl"}) unless options.parse
      @on 'change:dateModified', (model, value, options) =>
        metaHelper(value, {properties: "dcterms:modified"}) unless options.parse

      tagGroupHelper = (tagName, values, attributes) =>
        # make sure we actually have content
