diff --git a/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/cartridge.rs b/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/cartridge.rs
index a29bf76..aedded3 100644
--- a/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/cartridge.rs
+++ b/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/cartridge.rs
@@ -107,8 +107,24 @@ pub const CHEAPEST_PURCHASE: u32 = {
 /// 1 PKMN, 2 ITEM, 3 RUN".
 pub mod battle_entry {
     pub const FIGHT: u8 = 0;
-    pub const PKMN: u8 = 1;
-    pub const ITEM: u8 = 2;
+    /// `$01`. **The left column's second row, not the right column's first.**
+    ///
+    /// Red draws the battle menu as `FIGHT PKMN` over `ITEM RUN`, which reads as two rows -- and
+    /// the game's own index is two *columns*: `wCurrentMenuItem` is the row inside the column the
+    /// cursor is in and selection adds two for the right one. So the order is FIGHT, `ITEM`,
+    /// `PKMN`, RUN, and this pair was the other way round for as long as the four constants have
+    /// existed.
+    ///
+    /// **Measured on the cartridge** (2026-09-22, `infra/docs/macros-traps.md`): a `THROW BALL`
+    /// aiming at 2 walked the cursor to `wTopMenuItemX` 15, `wCurrentMenuItem` 0, pressed A, and
+    /// the **party list** opened -- `wTopMenuItemY` 1, `wTopMenuItemX` 0, `wListMenuID` `$02`.
+    /// The frame after the press the game wrote `wCurrentMenuItem` 2, which is the right column's
+    /// first row plus two, and the right column's first row is PKMN. So `THROW BALL` and `ITEM`
+    /// opened the party list and `SWITCH` opened the bag, every single time: `THROW BALL` was 63
+    /// starts and 63 `blocked` on v0.4.3, and `SWITCH` 15 of them.
+    pub const ITEM: u8 = 1;
+    /// `$02`. The right column's first row: see [`ITEM`].
+    pub const PKMN: u8 = 2;
     pub const RUN: u8 = 3;
 }
 
diff --git a/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/tests.rs b/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/tests.rs
index 12b3e1e..874180d 100644
--- a/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/tests.rs
+++ b/services/flysim/crates/flybrain-gb/src/pokemon_red/macros/tests.rs
@@ -448,12 +448,16 @@ impl World {
         }
         let here = i16::from(self.cursor);
         let target = if self.grid {
-            // Two rows of two: up and down change row, left and right change column.
+            // Red's battle menu: two **columns** of two, indexed by column. `wCurrentMenuItem` is
+            // the row inside the column the cursor is in and selection adds two for the right
+            // column, so the order is FIGHT, ITEM, PKMN, RUN -- up and down move one inside a
+            // column, left and right move two across (surveyed 2026-09-22; the fake had it
+            // row-major, which is the same mistake `battle_entry` had).
             match facing {
-                Facing::Down => here + 2,
-                Facing::Up => here - 2,
-                Facing::Right if here % 2 == 0 => here + 1,
-                Facing::Left if here % 2 == 1 => here - 1,
+                Facing::Down if here % 2 == 0 => here + 1,
+                Facing::Up if here % 2 == 1 => here - 1,
+                Facing::Right => here + 2,
+                Facing::Left => here - 2,
                 _ => here,
             }
         } else {
@@ -4378,6 +4382,40 @@ fn the_move_list_deals_back_only_where_the_moves_can_be_read() {
     assert_eq!(world.pulses.last(), Some(&buttons::A));
 }
 
+/// Section 12.11: Red's battle menu is two columns, so its order is FIGHT, ITEM, PKMN, RUN.
+///
+/// The screen reads `FIGHT PKMN` over `ITEM RUN` and the game's own index does not: it is the row
+/// inside the column the cursor is in, plus two for the right column. `battle_entry` had `PKMN` 1
+/// and `ITEM` 2, which is the row-major reading of the picture, so **every macro that opened the
+/// bag opened the party list and every macro that opened the party list opened the bag**.
+///
+/// **Surveyed on the cartridge** (`infra/docs/macros-traps.md`): a `THROW BALL` aiming at 2 walked
+/// the cursor to `wTopMenuItemX` 15 / `wCurrentMenuItem` 0, pressed A, and the party list opened --
+/// `wTopMenuItemY` 1, `wTopMenuItemX` 0, `wListMenuID` `$02` -- with the game writing
+/// `wCurrentMenuItem` 2 on the frame after the press. On v0.4.3 `THROW BALL` was 63 starts and 63
+/// `blocked`, and `SWITCH` 15 of them: never the macro's own list, always the other one.
+#[test]
+fn the_battle_menus_two_columns_put_item_under_fight_and_pkmn_beside_it() {
+    use super::cartridge::battle_entry;
+    assert_eq!(
+        [battle_entry::FIGHT, battle_entry::ITEM, battle_entry::PKMN, battle_entry::RUN],
+        [0, 1, 2, 3],
+        "the left column is FIGHT then ITEM, the right is PKMN then RUN"
+    );
+    // And the seam reads the same order back off the fake's own geometry: DOWN moves one inside a
+    // column, RIGHT moves two across.
+    let mut world = World::battle();
+    let menu = |world: &mut World| super::palette::battle_menu(world);
+    assert_eq!(menu(&mut world), BattleMenu::Main { cursor: battle_entry::FIGHT });
+    world.on_pulse(buttons::DOWN);
+    assert_eq!(menu(&mut world), BattleMenu::Main { cursor: battle_entry::ITEM });
+    world.on_pulse(buttons::UP);
+    world.on_pulse(buttons::RIGHT);
+    assert_eq!(menu(&mut world), BattleMenu::Main { cursor: battle_entry::PKMN });
+    world.on_pulse(buttons::DOWN);
+    assert_eq!(menu(&mut world), BattleMenu::Main { cursor: battle_entry::RUN });
+}
+
 /// Section 12.11: a cursor step waits for the list it was built for.
 ///
 /// **Measured on the cartridge, v0.4.3** (`infra/docs/macros-traps.md`): `THROW BALL` was **63
diff --git a/services/flysim/crates/flybrain-gb/src/pokemon_red/state.rs b/services/flysim/crates/flybrain-gb/src/pokemon_red/state.rs
index e409d76..da6167e 100644
--- a/services/flysim/crates/flybrain-gb/src/pokemon_red/state.rs
+++ b/services/flysim/crates/flybrain-gb/src/pokemon_red/state.rs
@@ -406,8 +406,14 @@ pub fn battle(memory: &mut dyn MemoryReader) -> Option<Battle> {
         && (left || right);
 
     let menu = if main {
-        // FIGHT and PKMN are the left column, ITEM and RUN the right; the cursor index the game
-        // keeps is within the column, and `.rightColumn` adds two to it on selection.
+        // **FIGHT and ITEM are the left column, PKMN and RUN the right.** The screen reads
+        // `FIGHT PKMN` over `ITEM RUN` and the game's index is by column: `wCurrentMenuItem` is
+        // the row inside the column the cursor is in, and `.rightColumn` adds two to it on
+        // selection -- so the order is FIGHT, ITEM, PKMN, RUN. Surveyed on the cartridge
+        // 2026-09-22 (`infra/docs/macros-traps.md`): A at `wTopMenuItemX` 15 with
+        // `wCurrentMenuItem` 0 opens the **party** list and the game then writes
+        // `wCurrentMenuItem` 2. `macros::cartridge::battle_entry` had this pair the other way
+        // round, so `ITEM` and `THROW BALL` opened the party list and `SWITCH` opened the bag.
         let column = if right { 2 } else { 0 };
         BattleMenu::Main { cursor: column + cursor.current.min(1) }
     } else if cursor.top_y == 12 && cursor.top_x == 5 {