diff --git a/client/scripts/main.gd b/client/scripts/main.gd
index 56514a1e7..2d3e5715a 100644
--- a/client/scripts/main.gd
+++ b/client/scripts/main.gd
@@ -19,8 +19,9 @@ extends Node2D
 
 var _last_dialogue_npc_id: int = -1  # D-064: NPC entity_id for WalkAway input
 var _camera_anchored: bool = false
-var _last_monologue_tick: int = -1  # Prevent re-consuming monologue when same tick polled twice
+var _last_monologue_tick: int = -1       # Prevent re-consuming monologue when same tick polled twice
 var _last_dialogue_tick: int = -1
+var _last_confrontation_tick: int = -1  # Deduplicate confrontation_monologue signals within same tick
 var _known_recognition_ids: Dictionary = {}  # D-067: entity_ids that have already chimed
 var _flash_rect: ColorRect = null  # #502/#501: ephemeral screen flash overlay (shared: teleport preempts amber)
 var _teleport_in_progress: bool = false  # #501: defer smoothing re-enable by one frame after teleport
@@ -338,9 +339,14 @@ func _on_dialogue_option_selected(response_id: String, text: String) -> void:
 
 # D-063: Handle confrontation beat monologue → show on monologue display (layer 7)
 # Confrontation lines are high-priority (3) and urgent — full opacity, elevated colour.
+# Tick guard deduplicates if dialogue box emits the signal multiple times in one tick.
 func _on_confrontation_monologue(text: String, duration: float) -> void:
-	if monologue_display:
-		monologue_display.show_monologue(text, duration, 3, true)
+	if not monologue_display:
+		return
+	if GameState.current_tick == _last_confrontation_tick:
+		return
+	_last_confrontation_tick = GameState.current_tick
+	monologue_display.show_monologue(text, duration, 3, true)
 
 
 # D-064: Handle walk-away → send WalkAway{npc_id} to server
diff --git a/client/tests/test_monologue_display.gd b/client/tests/test_monologue_display.gd
index 8b1c7a07c..151f5fb77 100644
--- a/client/tests/test_monologue_display.gd
+++ b/client/tests/test_monologue_display.gd
@@ -23,6 +23,8 @@ func _make_display() -> Node:
 
 
 func _label_text(d: Node) -> String:
+	if d._visible.is_empty():
+		return ""
 	var slot_node: Node = d._visible[0].node
 	return (slot_node.get_child(0) as RichTextLabel).text
 
@@ -456,10 +458,33 @@ func test_gamestate_monologue_replaced_by_next_snapshot() -> void:
 
 # ---------------------------------------------------------------------------
 # D-049 Z-layer / canvas scope compliance
-# Monologue display must be parented to CANVAS_UI (CanvasLayer 20), not the
-# world layer. This constant check ensures it hasn't silently drifted.
+# MonologueDisplay must be parented to UILayer (CanvasLayer, layer=20).
+# Two tests: (1) constant sanity, (2) scene tree structural verification.
 # ---------------------------------------------------------------------------
 
 func test_canvas_ui_constant_is_20() -> void:
 	## D-049: CANVAS_UI = 20 is the agreed HUD layer for monologue display.
+	## Sanity check — constant must not drift from the spec.
 	assert_that(Constants.CANVAS_UI).is_equal(20)
+
+
+func test_monologue_display_parented_to_canvas_layer_20_in_main_scene() -> void:
+	## D-049: Structural verification — MonologueDisplay must be a direct child of
+	## UILayer (CanvasLayer, layer=20) in the live scene tree, not the world layer.
+	## Catches regressions where the node gets accidentally moved to InsertOverlay
+	## (layer=10) or ModalLayer (layer=30), or dropped into the world z-stack.
+	##
+	## Scene path verified: Game/UILayer/MonologueDisplay (main.tscn line 141).
+	if not ResourceLoader.exists("res://scenes/main.tscn"):
+		push_warning("TestMonologueDisplay: main.tscn not found — D-049 scene tree test skipped")
+		return
+	var scene: Node = load("res://scenes/main.tscn").instantiate()
+	auto_free(scene)
+	add_child(scene)
+
+	var mono: Node = scene.get_node_or_null("UILayer/MonologueDisplay")
+	assert_that(mono != null).is_true()
+
+	var parent: Node = mono.get_parent()
+	assert_that(parent is CanvasLayer).is_true()
+	assert_that((parent as CanvasLayer).layer).is_equal(Constants.CANVAS_UI)
diff --git a/client/ui/monologue_display.gd b/client/ui/monologue_display.gd
index bf86501d6..38f3ec0dc 100644
--- a/client/ui/monologue_display.gd
+++ b/client/ui/monologue_display.gd
@@ -5,20 +5,22 @@ extends Control
 #
 # Up to MAX_VISIBLE lines display simultaneously in a VBoxContainer.
 # Additional arrivals queue up to MAX_QUEUE depth; lowest-priority entry is
-# dropped when the queue is full and a higher-priority line arrives.
+# dropped when the queue is full and an equal-or-higher-priority line arrives
+# (>= tiebreak = FIFO: newest replaces oldest at same priority).
 #
 # Stagger: 0.15s minimum gap between consecutive fade-ins (spec §5.4).
-# Colour: derived from GameState.lattice_profile at render time (D-032).
+# Colour: lattice_profile passed in at call time — no autoload access in renderer.
 # is_urgent=true → opacity 1.0 and elevated colour variant (bloom deferred).
 
 const MAX_VISIBLE: int = 3
 const MAX_QUEUE:   int = 5
 
-const STAGGER_SEC:  float = 0.15
-const FADE_IN_SEC:  float = 0.3
-const FADE_OUT_SEC: float = 0.5
+const STAGGER_SEC:   float = 0.15
+const FADE_IN_SEC:   float = 0.3
+const FADE_OUT_SEC:  float = 0.5
+const MIN_DURATION:  float = FADE_IN_SEC + 0.1  # clamp: line must survive its own fade-in
 
-# Lattice colour palette — keyed by GameState.lattice_profile.
+# Lattice colour palette — keyed by lattice_profile passed from GameState at show time.
 # standard opacity = 0.85, urgent opacity = 1.0.
 # Source: Tyre architecture review, Sprint 14.
 const _LATTICE_COLORS: Dictionary = {
@@ -38,7 +40,7 @@ const _FALLBACK_URGENT:   Color = Color("#e0e8f8")
 
 # Visible slot: {node: Control, expire_timer: float, priority: int, tween: Tween}
 var _visible: Array[Dictionary] = []
-# Queue entry: {text: String, duration: float, priority: int, is_urgent: bool}
+# Queue entry: {text, duration, priority, is_urgent, lattice_profile}
 var _queue: Array[Dictionary] = []
 # Msec timestamp when the next fade-in may begin (stagger enforcement)
 var _next_fade_in_msec: float = 0.0
@@ -60,34 +62,37 @@ func _process(delta: float) -> void:
 		var now := float(Time.get_ticks_msec())
 		if now >= _next_fade_in_msec:
 			var next: Dictionary = _queue.pop_front()
-			_show_line(next.text, next.duration, next.priority, next.is_urgent)
+			_show_line(next.text, next.duration, next.priority, next.is_urgent, next.lattice_profile)
 
 
 # Display a monologue line.
 # priority: higher number = more important (default 2; urgent beats normal).
 # is_urgent: visual flag — full opacity + elevated colour. Bloom deferred.
 # Empty text is silently ignored — no slot created, no queue entry.
+# lattice_profile is read from GameState here and passed down — renderer stays
+# decoupled from the autoload (D-020 renderer contract).
 func show_monologue(text: String, duration: float, priority: int = 2, is_urgent: bool = false) -> void:
 	if text.is_empty():
 		return
+	var profile := GameState.lattice_profile
 	var now := float(Time.get_ticks_msec())
 	if _visible.size() < MAX_VISIBLE and now >= _next_fade_in_msec:
-		_show_line(text, duration, priority, is_urgent)
+		_show_line(text, duration, priority, is_urgent, profile)
 	else:
-		_enqueue(text, duration, priority, is_urgent)
+		_enqueue(text, duration, priority, is_urgent, profile)
 
 
 # ---------------------------------------------------------------------------
 # Internal
 # ---------------------------------------------------------------------------
 
-func _show_line(text: String, duration: float, priority: int, is_urgent: bool) -> void:
-	var line_node := _build_line_node(text, is_urgent)
+func _show_line(text: String, duration: float, priority: int, is_urgent: bool, lattice_profile: String) -> void:
+	var line_node := _build_line_node(text, is_urgent, lattice_profile)
 	_vbox.add_child(line_node)
 
 	var slot := {
 		node         = line_node,
-		expire_timer = duration,
+		expire_timer = maxf(duration, MIN_DURATION),  # clamp: survives own fade-in
 		priority     = priority,
 		tween        = null as Tween,
 	}
@@ -112,17 +117,17 @@ func _retire_slot(slot: Dictionary) -> void:
 	tween.tween_callback(node.queue_free)
 
 
-func _enqueue(text: String, duration: float, priority: int, is_urgent: bool) -> void:
+func _enqueue(text: String, duration: float, priority: int, is_urgent: bool, lattice_profile: String) -> void:
 	if _queue.size() < MAX_QUEUE:
-		_queue.append({text = text, duration = duration, priority = priority, is_urgent = is_urgent})
+		_queue.append({text = text, duration = duration, priority = priority, is_urgent = is_urgent, lattice_profile = lattice_profile})
+		_queue.sort_custom(func(a: Dictionary, b: Dictionary) -> bool: return a.priority > b.priority)
 	else:
-		# Replace the lowest-priority queued entry if new one outranks it
+		# >= tiebreak: newest replaces oldest at equal priority (FIFO for equal ranks)
 		var lowest := _lowest_priority_idx()
-		if priority > _queue[lowest].priority:
-			_queue[lowest] = {text = text, duration = duration, priority = priority, is_urgent = is_urgent}
-		# else: incoming line is lower/equal priority — silently drop
-	# Re-sort: highest priority at front (next to display)
-	_queue.sort_custom(func(a: Dictionary, b: Dictionary) -> bool: return a.priority > b.priority)
+		if priority >= _queue[lowest].priority:
+			_queue[lowest] = {text = text, duration = duration, priority = priority, is_urgent = is_urgent, lattice_profile = lattice_profile}
+			_queue.sort_custom(func(a: Dictionary, b: Dictionary) -> bool: return a.priority > b.priority)
+		# else: incoming line is strictly lower priority — silently drop; no sort needed
 
 
 func _lowest_priority_idx() -> int:
@@ -133,9 +138,8 @@ func _lowest_priority_idx() -> int:
 	return idx
 
 
-func _build_line_node(text: String, is_urgent: bool) -> Control:
-	var profile: String = GameState.lattice_profile
-	var palette: Dictionary = _LATTICE_COLORS.get(profile, {})
+func _build_line_node(text: String, is_urgent: bool, lattice_profile: String) -> Control:
+	var palette: Dictionary = _LATTICE_COLORS.get(lattice_profile, {})
 	var color: Color = palette.get("urgent", _FALLBACK_URGENT) if is_urgent \
 		else palette.get("standard", _FALLBACK_STANDARD)
 
@@ -150,7 +154,10 @@ func _build_line_node(text: String, is_urgent: bool) -> Control:
 	label.fit_content = true
 	label.scroll_active = false
 	label.add_theme_font_size_override("normal_font_size", 13)
-	label.text = "[i][color=#%s]%s[/color][/i]" % [color.to_html(false), text]
+	# Escape [ to prevent BBCode injection from server-sourced text.
+	# [lb] is Godot's BBCode entity for a literal left bracket.
+	var safe_text := text.replace("[", "[lb]")
+	label.text = "[i][color=#%s]%s[/color][/i]" % [color.to_html(false), safe_text]
 
 	container.add_child(label)
 	return container
diff --git a/client/ui/monologue_display.tscn b/client/ui/monologue_display.tscn
index 47aaa1117..5e7ebf331 100644
--- a/client/ui/monologue_display.tscn
+++ b/client/ui/monologue_display.tscn
@@ -13,6 +13,7 @@ anchor_right = 0.55
 anchor_bottom = 0.98
 grow_horizontal = 1
 grow_vertical = 0
+clip_contents = true
 mouse_filter = 2
 script = ExtResource("1_monologue")