diff --git a/app/authorizers/timeline_authorizer.rb b/app/authorizers/timeline_authorizer.rb
new file mode 100644
index 00000000..1a4e3a0d
--- /dev/null
+++ b/app/authorizers/timeline_authorizer.rb
@@ -0,0 +1,31 @@
+class TimelineAuthorizer < ContentAuthorizer
+  def self.creatable_by?(user)
+    return false unless user.present?
+    return false if ENV.key?('CONTENT_BLACKLIST') && ENV['CONTENT_BLACKLIST'].split(',').include?(user.email)
+
+    return true if user.on_premium_plan?
+  end
+
+  def readable_by?(user)
+    return true if resource.privacy == 'public'
+    return true if user && resource.user_id == user.id
+    return true if resource.universe.present? && resource.universe.privacy == 'public'
+    return true if user && resource.universe.present? && resource.universe.user_id == user.id
+    return true if user && resource.universe.present? && resource.universe.contributors.pluck(:user_id).include?(user.id)
+    return true if user && user.site_administrator?
+
+    return false
+  end
+
+  def updatable_by?(user)
+    [
+      user && resource.user_id == user.id
+    ].any?
+  end
+
+  def deletable_by?(user)
+    [
+      user && resource.user_id == user.id
+    ].any?
+  end
+end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 4f578efc..efb66824 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -16,6 +16,12 @@ class ApplicationController < ActionController::Base
 
   private
 
+  def require_premium_plan
+    unless user_signed_in? && current_user.on_premium_plan?
+      return redirect_back(fallback_location: root_path, notice: "Doing that requires Premium access.")
+    end
+  end
+
   def set_metadata
     @page_title       ||= ''
     @page_keywords    ||= %w[writing author nanowrimo novel character fiction fantasy universe creative dnd roleplay game design]
diff --git a/app/controllers/page_tags_controller.rb b/app/controllers/page_tags_controller.rb
index 55653d39..ee41cc8a 100644
--- a/app/controllers/page_tags_controller.rb
+++ b/app/controllers/page_tags_controller.rb
@@ -1,4 +1,19 @@
 class PageTagsController < ApplicationController
+  def update
+    raise "placeholder"
+  end
+
+  def rename
+    old_tag_name = params[:tag].to_s
+    new_tag_name = params.dig(old_tag_name, :label)
+
+    if new_tag_name.blank?
+      new_tag_name = 'Untitled Tag'
+    end
+
+    current_user.page_tags.where(tag: old_tag_name).update_all(tag: new_tag_name)
+  end
+
   # Remove a tag and all of its links to a page
   def remove
     # Params
diff --git a/app/controllers/timelines_controller.rb b/app/controllers/timelines_controller.rb
index 3e243cce..2c67807d 100644
--- a/app/controllers/timelines_controller.rb
+++ b/app/controllers/timelines_controller.rb
@@ -5,15 +5,28 @@ class TimelinesController < ApplicationController
   before_action :set_navbar_color
   before_action :set_sidenav_expansion
 
+  before_action :require_premium_plan, only: [:new, :create]
+  before_action :require_timeline_read_permission, only: [:show]
+  before_action :require_timeline_edit_permission, only: [:edit, :update]
+
   # GET /timelines
   def index
     cache_linkable_content_for_each_content_type
 
+    # TODO: We SHOULD be just doing the below, but since it returns ContentPage stand-ins instead
+    # of actual Timeline models, it's a bit wonky to get all the Timeline-specific logic in place
+    # without reworking most of the views. For now, we're just grabbing timelines and contributable
+    # timelines manually.
+    # @timelines = @linkables_raw.fetch('Timeline', [])
     @timelines = current_user.timelines
+
     @page_title = "My timelines"
 
     if @universe_scope
-      @timelines = @timelines.where(universe: @universe_scope)
+      @timelines = Timeline.where(universe: @universe_scope)
+    else
+      # Add in all timelines from shared universes also
+      @timelines += Timeline.where(universe_id: current_user.contributable_universe_ids)
     end
 
     @page_tags = PageTag.where(
@@ -26,17 +39,12 @@ class TimelinesController < ApplicationController
     end
 
     # if params.key?(:favorite_only)
-    #   @content.select!(&:favorite?)
+    #   @timelines.select!(&:favorite?)
     # end
-
   end
 
   def show
     @page_title = @timeline.name
-
-    unless @timeline.privacy == 'public' || (user_signed_in? && current_user == @timeline.user)
-      return redirect_back(fallback_location: root_path, notice: "You don't have permission to view that timeline!")
-    end
   end
 
   # GET /timelines/new
@@ -47,11 +55,8 @@ class TimelinesController < ApplicationController
 
   # GET /timelines/1/edit
   def edit
-    @page_title = "Editing " + @timeline.name
-    
+    @page_title = "Editing #{@timeline.name}"
     @suggested_page_tags = []
-
-    raise "No Access"   unless user_signed_in? && current_user == @timeline.user
   end
 
   # POST /timelines
@@ -70,8 +75,6 @@ class TimelinesController < ApplicationController
 
   # PATCH/PUT /timelines/1
   def update
-    return unless user_signed_in? && current_user == @timeline.user
-
     if @timeline.update(timeline_params)
       update_page_tags
 
@@ -89,6 +92,14 @@ class TimelinesController < ApplicationController
 
   private
 
+  def require_timeline_read_permission
+    return user_signed_in? && @timeline.readable_by?(current_user)
+  end
+
+  def require_timeline_edit_permission
+    return user_signed_in? && @timeline.updatable_by?(current_user)
+  end
+
   # TODO: move this (and the copy in ContentController) into the has_page_tags concern?
   def update_page_tags
     tag_list = page_tag_params.split(PageTag::SUBMISSION_DELIMITER)
diff --git a/app/models/timelines/timeline.rb b/app/models/timelines/timeline.rb
index 8efa143f..e12d6449 100644
--- a/app/models/timelines/timeline.rb
+++ b/app/models/timelines/timeline.rb
@@ -8,7 +8,7 @@ class Timeline < ApplicationRecord
   include BelongsToUniverse
 
   include Authority::Abilities
-  self.authorizer_name = 'ExtendedContentAuthorizer'
+  self.authorizer_name = 'TimelineAuthorizer'
 
   validates :user_id, presence: true
   belongs_to :user
diff --git a/app/views/data/tags.html.erb b/app/views/data/tags.html.erb
index ee09258f..8d761639 100644
--- a/app/views/data/tags.html.erb
+++ b/app/views/data/tags.html.erb
@@ -35,21 +35,35 @@
                   </span>
                 <% end %>
               </div>
-              <div class="grey-text" style="padding-top: 1em">
-                Used by <%= pluralize page_list.length, 'page' %>
-              </div>
+              <br />
               <div>
+                <%= form_for tag, url: rename_tag_path(tag: tag) do |f| %>
+                  <div class="row">
+                    <div class="input-field col s12 m12 l12">
+                      <%= f.text_field :label, class: '', value: tag %>
+                      <%= f.label :label, 'Rename tag' %>
+                    </div>
+                    <div class="col s12 m12 l12">
+                      <%= f.submit 'Mass-rename', class: 'btn white blue-text', onclick: "javascript: M.toast({ html: 'Saving changes...' });" %>
+                    </div>
+                  </div>
+                <% end %>
+              </div>
+              <div style="text-align: right">
                 <%=
                   link_to 'Delete this tag', tag_remove_path(
                     page_type: content_type.name,
                     slug: PageTagService.slug_for(tag)
                   ), data: {
                     confirm: "Are you sure? This will delete this tag and remove it from all pages."
-                  }, class: 'red-text'
+                  }, class: 'red-text btn red white-text'
                 %>
               </div>
             </div>
             <div class="col s12 m6 l8">
+              <div class="grey-text" style="padding-top: 1em">
+                Used by <%= pluralize page_list.length, 'page' %>
+              </div>
               <% page_list.each do |page_tag| %>
                 <div class="chip js-load-page-name" data-klass="<%= page_tag.page_type %>" data-id="<%= page_tag.page_id %>">
                   <%= link_to send("#{page_tag.page_type.downcase}_path", page_tag.page_id) do %>
diff --git a/app/views/timelines/index.html.erb b/app/views/timelines/index.html.erb
index 8a685a4a..8389bbd9 100644
--- a/app/views/timelines/index.html.erb
+++ b/app/views/timelines/index.html.erb
@@ -59,13 +59,17 @@
 
             </div>
             <div class="card-action">
-              <%= link_to timeline_path(timeline), class: 'blue-text left' do %>
-                <i class="material-icons left"><%= Timeline.icon %></i>
-                View
+              <% if timeline.readable_by?(current_user) %>
+                <%= link_to timeline_path(timeline), class: 'blue-text left' do %>
+                  <i class="material-icons left"><%= Timeline.icon %></i>
+                  View
+                <% end %>
               <% end %>
-              <%= link_to edit_timeline_path(timeline), class: 'green-text right' do %>
-                <i class="material-icons left">edit</i>
-                Edit
+              <% if timeline.updatable_by?(current_user) %>
+                <%= link_to edit_timeline_path(timeline), class: 'green-text right' do %>
+                  <i class="material-icons left">edit</i>
+                  Edit
+                <% end %>
               <% end %>
               <div class="clearfix"></div>
             </div>
diff --git a/config/attributes/school.yml b/config/attributes/school.yml
index 71476cdb..da8f83b3 100644
--- a/config/attributes/school.yml
+++ b/config/attributes/school.yml
@@ -89,6 +89,8 @@
       :label: Past students
     - :name: famous_students
       :label: Famous students
+    - :name: headcount
+      :label: Headcount
 :extracurriculars:
   :label: Extracurriculars
   :icon: rowing
diff --git a/config/routes.rb b/config/routes.rb
index 0becf658..e2ddef15 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -98,7 +98,9 @@ Rails.application.routes.draw do
 
     get '/scratchpad',      to: 'main#notes', as: :notes
 
-    get 'tag/remove',       to: 'page_tags#remove'
+    get 'tag/remove',         to: 'page_tags#remove'
+    # post 'tag/:slug/update',  to: 'page_tags#update',  as: :update_tag
+    post '/tag/:tag/rename', to: 'page_tags#rename', as: :rename_tag
     delete 'tag/:id/destroy', to: 'page_tags#destroy', as: :destroy_specific_tag
 
     # Legacy route: left intact so /my/documents/X URLs continue to work for everyone's bookmarks