diff --git a/plugins/chat/app/models/chat_message.rb b/plugins/chat/app/models/chat_message.rb
index 2c07386bb3..145144ad79 100644
--- a/plugins/chat/app/models/chat_message.rb
+++ b/plugins/chat/app/models/chat_message.rb
@@ -90,7 +90,7 @@ class ChatMessage < ActiveRecord::Base
     return uploads.first.original_filename if cooked.blank? && uploads.present?
 
     # this may return blank for some complex things like quotes, that is acceptable
-    PrettyText.excerpt(cooked, 50, {})
+    PrettyText.excerpt(cooked, 50, { text_entities: true })
   end
 
   def cooked_for_excerpt
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-desktop.hbs b/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-desktop.hbs
index 7b328c671b..07d9d99fa3 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-desktop.hbs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-message-actions-desktop.hbs
@@ -42,6 +42,7 @@
         @class="btn-flat chat-message-thread-btn"
         @action={{this.messageActions.showThread}}
         @icon="puzzle-piece"
+        @title="chat.threads.open"
       />
     {{/if}}
 
diff --git a/plugins/chat/assets/javascripts/discourse/components/chat-thread.hbs b/plugins/chat/assets/javascripts/discourse/components/chat-thread.hbs
index fc639a71ce..7ae72eadba 100644
--- a/plugins/chat/assets/javascripts/discourse/components/chat-thread.hbs
+++ b/plugins/chat/assets/javascripts/discourse/components/chat-thread.hbs
@@ -1,6 +1,6 @@
-<div class="chat-thread">
+<div class="chat-thread" data-id={{this.thread.id}}>
   <div class="chat-thread__header">
-    <div class="chat-thread__info" id="info-desktop">
+    <div class="chat-thread__info">
       <div class="chat-thread__title">
         <h2>{{this.title}}</h2>
 
diff --git a/plugins/chat/config/locales/client.en.yml b/plugins/chat/config/locales/client.en.yml
index 056c18be9a..a72cfde032 100644
--- a/plugins/chat/config/locales/client.en.yml
+++ b/plugins/chat/config/locales/client.en.yml
@@ -67,7 +67,7 @@ en:
       channel_delete:
         title: "Delete Channel"
         instructions: "<p>Deletes the <strong>%{name}</strong> channel and chat history. All messages and related data, such as reactions and uploads, will be permanently deleted. If you want to preserve the channel history and decomission it, you may want to archive the channel instead.</p>
-        <p>Are you sure you want to <strong>permanently delete</strong> the channel? To confirm, type the name of the channel in the box below.</p>"
+          <p>Are you sure you want to <strong>permanently delete</strong> the channel? To confirm, type the name of the channel in the box below.</p>"
         confirm: "I understand the consequences, delete the channel"
         confirm_channel_name: "Enter channel name"
         process_started: "The process to delete the channel has started. This modal will close shortly, you will no longer see the deleted channel anywhere."
@@ -444,6 +444,7 @@ en:
 
       threads:
         op_said: "OP said:"
+        open: "Open Thread"
 
       draft_channel_screen:
         header: "New Message"
diff --git a/plugins/chat/spec/plugin_helper.rb b/plugins/chat/spec/plugin_helper.rb
index 33657da1fc..f7e5c00155 100644
--- a/plugins/chat/spec/plugin_helper.rb
+++ b/plugins/chat/spec/plugin_helper.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "faker"
+
 module ChatSystemHelpers
   def chat_system_bootstrap(user = Fabricate(:admin), channels_for_membership = [])
     # ensures we have one valid registered admin/user
@@ -20,6 +22,31 @@ module ChatSystemHelpers
     # this is reset after each test
     Bookmark.register_bookmarkable(ChatMessageBookmarkable)
   end
+
+  def chat_thread_chain_bootstrap(channel:, users:, messages_count: 4)
+    last_user = nil
+    last_message = nil
+
+    messages_count.times do |i|
+      in_reply_to = i.zero? ? nil : last_message.id
+      thread_id = i.zero? ? nil : last_message.thread_id
+      last_user = last_user.present? ? (users - [last_user]).sample : users.sample
+      creator =
+        Chat::ChatMessageCreator.new(
+          chat_channel: channel,
+          in_reply_to_id: in_reply_to,
+          thread_id: thread_id,
+          user: last_user,
+          content: Faker::Lorem.paragraph,
+        )
+      creator.create
+
+      raise creator.error if creator.error
+      last_message = creator.chat_message
+    end
+
+    last_message.thread
+  end
 end
 
 RSpec.configure { |config| config.include ChatSystemHelpers, type: :system }
diff --git a/plugins/chat/spec/system/page_objects/chat/chat_channel.rb b/plugins/chat/spec/system/page_objects/chat/chat_channel.rb
index 715c2a3d2e..ad7d3bb043 100644
--- a/plugins/chat/spec/system/page_objects/chat/chat_channel.rb
+++ b/plugins/chat/spec/system/page_objects/chat/chat_channel.rb
@@ -51,6 +51,11 @@ module PageObjects
         find("[data-value='flag']").click
       end
 
+      def open_message_thread(message)
+        hover_message(message)
+        find(".chat-message-thread-btn").click
+      end
+
       def select_message(message)
         hover_message(message)
         click_more_buttons(message)
diff --git a/plugins/chat/spec/system/page_objects/chat/chat_side_panel.rb b/plugins/chat/spec/system/page_objects/chat/chat_side_panel.rb
new file mode 100644
index 0000000000..01dfb1f2da
--- /dev/null
+++ b/plugins/chat/spec/system/page_objects/chat/chat_side_panel.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module PageObjects
+  module Pages
+    class ChatSidePanel < PageObjects::Pages::Base
+      def has_open_thread?(thread)
+        has_css?(".chat-side-panel .chat-thread[data-id='#{thread.id}']")
+      end
+    end
+  end
+end
diff --git a/plugins/chat/spec/system/page_objects/chat/chat_thread.rb b/plugins/chat/spec/system/page_objects/chat/chat_thread.rb
new file mode 100644
index 0000000000..7835e0721e
--- /dev/null
+++ b/plugins/chat/spec/system/page_objects/chat/chat_thread.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module PageObjects
+  module Pages
+    class ChatThread < PageObjects::Pages::Base
+      def has_header_content?(content)
+        find(".chat-thread__header").has_content?(content)
+      end
+    end
+  end
+end
diff --git a/plugins/chat/spec/system/single_thread_spec.rb b/plugins/chat/spec/system/single_thread_spec.rb
new file mode 100644
index 0000000000..6a3a774469
--- /dev/null
+++ b/plugins/chat/spec/system/single_thread_spec.rb
@@ -0,0 +1,64 @@
+# frozen_string_literal: true
+
+describe "Single thread in side panel", type: :system, js: true do
+  fab!(:current_user) { Fabricate(:user) }
+
+  let(:chat_page) { PageObjects::Pages::Chat.new }
+  let(:channel_page) { PageObjects::Pages::ChatChannel.new }
+  let(:side_panel) { PageObjects::Pages::ChatSidePanel.new }
+  let(:open_thread) { PageObjects::Pages::ChatThread.new }
+
+  before do
+    chat_system_bootstrap(current_user, [channel])
+    sign_in(current_user)
+  end
+
+  context "when enable_experimental_chat_threaded_discussions is disabled" do
+    fab!(:channel) { Fabricate(:chat_channel) }
+    before { SiteSetting.enable_experimental_chat_threaded_discussions = false }
+
+    it "does not open the side panel for a single thread" do
+      thread =
+        chat_thread_chain_bootstrap(channel: channel, users: [current_user, Fabricate(:user)])
+      chat_page.visit_channel(channel)
+      channel_page.hover_message(thread.original_message)
+      expect(page).not_to have_css(".chat-message-thread-btn")
+    end
+  end
+
+  context "when threading_enabled is false for the channel" do
+    fab!(:channel) { Fabricate(:chat_channel) }
+    before do
+      SiteSetting.enable_experimental_chat_threaded_discussions = true
+      channel.update!(threading_enabled: false)
+    end
+
+    it "does not open the side panel for a single thread" do
+      thread =
+        chat_thread_chain_bootstrap(channel: channel, users: [current_user, Fabricate(:user)])
+      chat_page.visit_channel(channel)
+      channel_page.hover_message(thread.original_message)
+      expect(page).not_to have_css(".chat-message-thread-btn")
+    end
+  end
+
+  context "when enable_experimental_chat_threaded_discussions is true and threading is enabled for the channel" do
+    fab!(:user_2) { Fabricate(:user) }
+    fab!(:channel) { Fabricate(:chat_channel, threading_enabled: true) }
+    fab!(:thread) { chat_thread_chain_bootstrap(channel: channel, users: [current_user, user_2]) }
+
+    before { SiteSetting.enable_experimental_chat_threaded_discussions = true }
+
+    it "opens the side panel for a single thread from the message actions menu" do
+      chat_page.visit_channel(channel)
+      channel_page.open_message_thread(thread.original_message)
+      expect(side_panel).to have_open_thread(thread)
+    end
+
+    it "shows the excerpt of the thread original message" do
+      chat_page.visit_channel(channel)
+      channel_page.open_message_thread(thread.original_message)
+      expect(open_thread).to have_header_content(thread.original_message.excerpt)
+    end
+  end
+end
diff --git a/spec/rails_helper.rb b/spec/rails_helper.rb
index c822777e70..e526c685b9 100644
--- a/spec/rails_helper.rb
+++ b/spec/rails_helper.rb
@@ -283,13 +283,13 @@ RSpec.configure do |config|
         end
 
     Capybara.register_driver :selenium_chrome do |app|
-      Capybara::Selenium::Driver.new(app, browser: :chrome, capabilities: chrome_browser_options)
+      Capybara::Selenium::Driver.new(app, browser: :chrome, options: chrome_browser_options)
     end
 
     Capybara.register_driver :selenium_chrome_headless do |app|
       chrome_browser_options.add_argument("--headless")
 
-      Capybara::Selenium::Driver.new(app, browser: :chrome, capabilities: chrome_browser_options)
+      Capybara::Selenium::Driver.new(app, browser: :chrome, options: chrome_browser_options)
     end
 
     mobile_chrome_browser_options =
@@ -304,20 +304,12 @@ RSpec.configure do |config|
         end
 
     Capybara.register_driver :selenium_mobile_chrome do |app|
-      Capybara::Selenium::Driver.new(
-        app,
-        browser: :chrome,
-        capabilities: mobile_chrome_browser_options,
-      )
+      Capybara::Selenium::Driver.new(app, browser: :chrome, options: mobile_chrome_browser_options)
     end
 
     Capybara.register_driver :selenium_mobile_chrome_headless do |app|
       mobile_chrome_browser_options.add_argument("--headless")
-      Capybara::Selenium::Driver.new(
-        app,
-        browser: :chrome,
-        capabilities: mobile_chrome_browser_options,
-      )
+      Capybara::Selenium::Driver.new(app, browser: :chrome, options: mobile_chrome_browser_options)
     end
 
     if ENV["ELEVATED_UPLOADS_ID"]