diff --git a/docs/index.rst b/docs/index.rst
index 92686cc61c..0de0483409 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -56,3 +56,8 @@ For a list of all ``google-cloud-spanner`` releases:
   :maxdepth: 2
 
   changelog
+
+.. toctree::
+  :hidden:
+
+  summary_overview.md