diff --git a/book/_toc.yml b/book/_toc.yml
index 6c77dc0..4ff54db 100644
--- a/book/_toc.yml
+++ b/book/_toc.yml
@@ -35,6 +35,7 @@ parts:
       - file: features/remove_from_publish
       - file: features/custom_toc.md
       - file: features/custom_download.md
+      - file: external/Nested-Books/README.md
       - file: features/interactive_element.ipynb
         sections:
         - file: features/grasple.md
diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index 8ea5a17..0274cf7 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit 8ea5a179daab16358ebcf1620638479fe5fdeea1
+Subproject commit 0274cf7cce4e0ff084de4b131d5b3b30c3a697c0