diff --git a/Items/book_of_secrets.asm b/Items/book_of_secrets.asm
index 28ebb8a..04323d2 100644
--- a/Items/book_of_secrets.asm
+++ b/Items/book_of_secrets.asm
@@ -1,9 +1,8 @@
-; =============================================================================
+; =========================================================
 ; Book of Secrets (Reveal Secrets with Book of Mudora)
-; Makes BG2 Disappear when pressing X+R
+; Makes BG2 Disappear when holding L in a building
 ; Based on the Parallel Worlds feature
 ;
-; Bank 0x3C used for whole code
 ; Layer Flags: xxxsabcd (i count BG from 1 to 4 - MathOnNapkins RAM-Map counts from 0 to 3)
 ; s - Sprite layer enabled 
 ; a - BG4 enabled
@@ -11,45 +10,39 @@
 ; c - BG2 enabled
 ; d - (BG1 disabled) --> only works properly if the room uses the feature "BG2 on Top"
 ;
-; Written by XaserLE
-; Edited by scawful
-; =============================================================================
+; Originally by XaserLE, updated by scawful
 
-; =============================================================================
-; code that branches behind the dungeon map load if player didn't press X
-org $0288FD			  
-BRA $1C				    ; make it always branch, so map isn't loaded anymore
-
-; =============================================================================
+; =========================================================
 ; long subroutine that is executed every frame
-org $068365			  
-JSL LinkItem_SecretsBook			  ; overwrite it (originally JSL $099F91)
 
-; =============================================================================
+org $068365			  
+JSL LinkItem_SecretsBook ; overwrite it (originally JSL $099F91)
+
+; =========================================================
 
 pullpc
 
 LinkItem_SecretsBook:
 {
-  LDA $1B				    ; load data that tells us whether we are in a building or not
-  AND #$01			    ; are we in a building?
-  BEQ .end				    ; if not, don't use the x-button-secret
+  ; Check if we are in a building
+  LDA $1B : AND #$01 : BEQ .end
 
     ; ----------
-    LDA $7EF34D			; load book of mudora slot
-    CMP #$01			  ; do we have the moon pearl?
-    BNE $0F				  ; if not, go to enable BG2
-    LDA $F2				  ; load unfiltered joypad 1 register (AXLR|????)
-    AND #$50 			  ; delete all bits except those for X and R
-    SEC 				    ; set carry for the following subtraction
-    SBC #$50			  ; X+R button pressed? (if yes, zero flag is set)
-    BNE $06				  ; if not, go to enable BG2
-      LDA $1C				; load layer flags
-      AND #$FD			; disable BG2 (0xFD = 11111101)
-      BRA $04				; go to store layer flags
-    LDA $1C				  ; load layer flags
-    ORA #$02			  ; enable BG2 (0x02 = 00000010)
-    STA $1C				  ; store layer flags
+    ; Check if we have the book of secrets
+    LDA $7EF34D : CMP #$01 : BNE $0F ; if not, go to enable BG2
+
+    ; load unfiltered joypad 1 register (AXLR|????)
+    ; delete all bits except those for L
+    LDA $F2	: AND #$20 
+
+    ; L button pressed? (if yes, zero flag is set)
+    SEC : SBC #$20	: BNE $06	; if not, go to enable BG2
+
+      ; load layer flags and disable BG2 (0xFD = 11111101)
+      LDA $1C	: AND #$FD : BRA $04 ; go to store layer flags
+    
+    ; enable BG2 (0x02 = 00000010)
+    LDA $1C	: ORA #$02 : STA $1C				  
     ; ----------
 
 .end
@@ -59,6 +52,3 @@ LinkItem_SecretsBook:
 
 print  "End of Items/book_of_secrets.asm  ", pc
 pushpc
-
-
-; =============================================================================
\ No newline at end of file