diff --git a/code-validation/src/lib.rs b/code-validation/src/lib.rs
index 2c92a6b3b8..d8a75179ad 100644
--- a/code-validation/src/lib.rs
+++ b/code-validation/src/lib.rs
@@ -44,20 +44,20 @@ mod learn {
         mod ecs {
             #[doc = include_str!("../../content/learn/book/ecs/commands/_index.md")]
             mod commands {}
+            #[doc = include_str!("../../content/learn/book/ecs/detecting-changes/_index.md")]
+            mod detecting_changes {}
+            #[doc = include_str!("../../content/learn/book/ecs/ecs-magic/_index.md")]
+            mod ecs_magic {}
             #[doc = include_str!("../../content/learn/book/ecs/entities-components/_index.md")]
             mod entities_components {}
             #[doc = include_str!("../../content/learn/book/ecs/exclusive-world-access/_index.md")]
             mod exclusive_world_access {}
-            #[doc = include_str!("../../content/learn/book/ecs/filtering-queries/_index.md")]
-            mod filtering_queries {}
-            #[doc = include_str!("../../content/learn/book/ecs/generic-systems/_index.md")]
-            mod generic_systems {}
-            #[doc = include_str!("../../content/learn/book/ecs/reliable-change-detection/_index.md")]
-            mod reliable_change_detection {}
+            #[doc = include_str!("../../content/learn/book/ecs/queries/_index.md")]
+            mod queries {}
             #[doc = include_str!("../../content/learn/book/ecs/resources/_index.md")]
             mod resources {}
-            #[doc = include_str!("../../content/learn/book/ecs/systems-queries/_index.md")]
-            mod system_queries {}
+            #[doc = include_str!("../../content/learn/book/ecs/systems/_index.md")]
+            mod systems {}
         }
 
         #[doc = include_str!("../../content/learn/book/game-logic/_index.md")]
diff --git a/content/learn/book/ecs/commands/_index.md b/content/learn/book/ecs/commands/_index.md
index 244474425a..54bc282f45 100644
--- a/content/learn/book/ecs/commands/_index.md
+++ b/content/learn/book/ecs/commands/_index.md
@@ -1,13 +1,7 @@
 +++
-title = "Manipulating entities with commands"
-weight = 4
+title = "Commands queue up work"
+weight = 5
 template = "book-section.html"
 page_template = "book-section.html"
 insert_anchor_links = "right"
 +++
-
-TODO: explain what commands are used for
-
-TODO: explain that they only run at the end of the stage, mention that they have exclusive world access
-
-TODO: show how to spawn, despawn and modify entities with commands
diff --git a/content/learn/book/ecs/detecting-changes/_index.md b/content/learn/book/ecs/detecting-changes/_index.md
new file mode 100644
index 0000000000..b456af0b73
--- /dev/null
+++ b/content/learn/book/ecs/detecting-changes/_index.md
@@ -0,0 +1,7 @@
++++
+title = "Detecting changes"
+weight = 6
+template = "book-section.html"
+page_template = "book-section.html"
+insert_anchor_links = "right"
++++
\ No newline at end of file
diff --git a/content/learn/book/ecs/ecs-magic/_index.md b/content/learn/book/ecs/ecs-magic/_index.md
new file mode 100644
index 0000000000..fc9b440a59
--- /dev/null
+++ b/content/learn/book/ecs/ecs-magic/_index.md
@@ -0,0 +1,7 @@
++++
+title = "Understanding the magic"
+weight = 8
+template = "book-section.html"
+page_template = "book-section.html"
+insert_anchor_links = "right"
++++
\ No newline at end of file
diff --git a/content/learn/book/ecs/exclusive-world-access/_index.md b/content/learn/book/ecs/exclusive-world-access/_index.md
index 66eb6e691c..3dc6470583 100644
--- a/content/learn/book/ecs/exclusive-world-access/_index.md
+++ b/content/learn/book/ecs/exclusive-world-access/_index.md
@@ -1,6 +1,6 @@
 +++
-title = "Exclusive `World` access"
-weight = 8
+title = "Exclusive world access"
+weight = 7
 template = "book-section.html"
 page_template = "book-section.html"
 insert_anchor_links = "right"
diff --git a/content/learn/book/ecs/filtering-queries/_index.md b/content/learn/book/ecs/filtering-queries/_index.md
deleted file mode 100644
index a5c198b3a4..0000000000
--- a/content/learn/book/ecs/filtering-queries/_index.md
+++ /dev/null
@@ -1,17 +0,0 @@
-+++
-title = "Filtering queries"
-weight = 5
-template = "book-section.html"
-page_template = "book-section.html"
-insert_anchor_links = "right"
-+++
-
-TODO: explain that queries fetch data of all the components at once
-
-TODO: demonstrate With filters
-
-TODO: demonstrate Without filters
-
-TODO: explain marker component pattern
-
-TODO: explain how to use `Or` and `Option` to create very complex queries
diff --git a/content/learn/book/ecs/generic-systems/_index.md b/content/learn/book/ecs/generic-systems/_index.md
deleted file mode 100644
index ed81ba5094..0000000000
--- a/content/learn/book/ecs/generic-systems/_index.md
+++ /dev/null
@@ -1,13 +0,0 @@
-+++
-title = "Generic systems"
-weight = 7
-template = "book-section.html"
-page_template = "book-section.html"
-insert_anchor_links = "right"
-+++
-
-TODO: refresh on generics in Rust
-
-TODO: motivate use (many similar systems)
-
-TODO: demonstrate
diff --git a/content/learn/book/ecs/queries/_index.md b/content/learn/book/ecs/queries/_index.md
new file mode 100644
index 0000000000..edc16b65a3
--- /dev/null
+++ b/content/learn/book/ecs/queries/_index.md
@@ -0,0 +1,7 @@
++++
+title = "Fetching data with queries"
+weight = 2
+template = "book-section.html"
+page_template = "book-section.html"
+insert_anchor_links = "right"
++++
diff --git a/content/learn/book/ecs/reliable-change-detection/_index.md b/content/learn/book/ecs/reliable-change-detection/_index.md
deleted file mode 100644
index a9ea5efea5..0000000000
--- a/content/learn/book/ecs/reliable-change-detection/_index.md
+++ /dev/null
@@ -1,17 +0,0 @@
-+++
-title = "Reliable change detection"
-weight = 6
-template = "book-section.html"
-page_template = "book-section.html"
-insert_anchor_links = "right"
-+++
-
-TODO: discuss the need to only respond on changed data
-
-TODO: demonstrate Changed filters
-
-TODO: discuss the need to only respond to added data
-
-TODO: demonstrate Added filters
-
-TODO: link to Leafwings blog post (possibly cross-post to Bevy blog) for technical details
diff --git a/content/learn/book/ecs/systems-queries/_index.md b/content/learn/book/ecs/systems-queries/_index.md
deleted file mode 100644
index 68a693f4ad..0000000000
--- a/content/learn/book/ecs/systems-queries/_index.md
+++ /dev/null
@@ -1,17 +0,0 @@
-+++
-title = "Systems access data through queries"
-weight = 2
-template = "book-section.html"
-page_template = "book-section.html"
-insert_anchor_links = "right"
-+++
-
-TODO: Explain what a system is
-
-TODO: Explain what a query is
-
-TODO: show how to create your first system
-
-TODO: show how to access entity data through simple queries
-
-TODO: discuss queries for `Entity` and `query.get`
diff --git a/content/learn/book/ecs/systems/_index.md b/content/learn/book/ecs/systems/_index.md
new file mode 100644
index 0000000000..d130159102
--- /dev/null
+++ b/content/learn/book/ecs/systems/_index.md
@@ -0,0 +1,8 @@
++++
+title = "Systems do work"
+weight = 4
+template = "book-section.html"
+page_template = "book-section.html"
+insert_anchor_links = "right"
++++
+