diff --git a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/electromagnetism/n1/textbook.en.md b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/electromagnetism/n1/textbook.en.md
index 526353a8f..7e538c28c 100644
--- a/00.brainstorming-pedagogical-teams/45.synthesis-structuring/electromagnetism/n1/textbook.en.md
+++ b/00.brainstorming-pedagogical-teams/45.synthesis-structuring/electromagnetism/n1/textbook.en.md
@@ -6,8 +6,6 @@ visible: false
 lessons:
     - slug: brainstorming-123-electromagnetism
       order: 1
-    - slug: brainstorming-234-electromagnetism
-      order: 4
 ---
 
 #### Brainstorming to structure a theme "Electromagnetism" : level 1