diff --git a/crates/effects/src/lib.rs b/crates/effects/src/lib.rs
index e86adec96..758d690ba 100644
--- a/crates/effects/src/lib.rs
+++ b/crates/effects/src/lib.rs
@@ -354,8 +354,8 @@ pub trait EffectHost: Sync {
         self.layer(id, false)
     }
     /// The effect's own layer at another **layer time** `layer_time` (seconds): its source with
-    /// masks applied, followed by the first `effects` effects of its stack (0 = none, which is
-    /// what After Effects' Time effects see). `None` when unavailable (no host, recursion
+    /// masks applied, followed by the first `effects` effects of its stack (0 = none; the host
+    /// never goes past the effect being rendered). `None` when unavailable (no host, recursion
     /// limit, adjustment layers). Time effects use this to read neighbouring frames.
     fn self_at(&self, _layer_time: f64, _effects: usize) -> Option<Buf> {
         None
diff --git a/crates/effects/src/time_fx.rs b/crates/effects/src/time_fx.rs
index d455ce039..27d2264e5 100644
--- a/crates/effects/src/time_fx.rs
+++ b/crates/effects/src/time_fx.rs
@@ -1,10 +1,11 @@
 //! Time effects (Effect > Time): Echo, Posterize Time, Time Difference, Time Displacement,
 //! Timewarp, CC Force Motion Blur, CC Wide Time and Pixel Motion Blur.
 //!
-//! These read the layer at *other* layer times through [`EffectHost::self_at`] with zero
-//! preceding effects: like After Effects' Time effects they see the layer's source with its
-//! masks and ignore effects applied before them (precompose to include those). Without a host
-//! (tests, thumbnails) they pass their input through.
+//! These read the layer at *other* layer times through [`EffectHost::self_at`]: its source with
+//! its masks and the effects applied before them, as After Effects renders them (SceneYard:
+//! Echo after CC Particle Systems II echoes the fireworks, not the black solid under them;
+//! Posterize Time after Turbulent Displace steps the displacement). Without a host (tests,
+//! thumbnails) they pass their input through.
 //!
 //! Timewarp's Pixel Motion estimates block-matching optical flow between neighbouring frames
 //! ([`effectcraft_raster::flow`]); Pixel Motion Blur averages sub-frame samples.
@@ -169,7 +170,8 @@ fn fetch(ctx: &EffectCtx, times: &[f64]) -> Option<Frames> {
     let mut uniq: Vec<i64> = times.iter().map(|t| (t * 1e6).round() as i64).collect();
     uniq.sort_unstable();
     uniq.dedup();
-    let bufs: Vec<(i64, Option<Buf>)> = uniq.iter().map(|&k| (k, host.self_at(k as f64 / 1e6, 0))).collect();
+    // Every effect before this one (the host bounds the count to them).
+    let bufs: Vec<(i64, Option<Buf>)> = uniq.iter().map(|&k| (k, host.self_at(k as f64 / 1e6, usize::MAX))).collect();
     let first = bufs.iter().find_map(|(_, b)| b.as_ref())?;
     let scale = first.scale;
     // Union of every frame's extent in layer pixels (offset = where layer (0,0) sits).
@@ -1014,7 +1016,8 @@ mod tests {
             None
         }
         fn self_at(&self, t: f64, effects: usize) -> Option<Buf> {
-            assert_eq!(effects, 0);
+            // Time effects see every effect before them.
+            assert_eq!(effects, usize::MAX);
             let v = if self.static_layer { 0.4 } else { t as f32 };
             Some(Buf { img: Image::filled(6, 4, [v, v, v, 1.0]), offset: [0.0; 2], scale: 1.0 })
         }
diff --git a/crates/render/src/tests_time.rs b/crates/render/src/tests_time.rs
index 31ed9db3c..8739140de 100644
--- a/crates/render/src/tests_time.rs
+++ b/crates/render/src/tests_time.rs
@@ -64,6 +64,22 @@ fn echo_blends_neighbouring_frames() {
     assert!((a - want).abs() < 0.01, "{a} vs {want}");
 }
 
+/// Time effects see the effects applied before them, as After Effects renders them (SceneYard
+/// "Task Preparation UI": Echo after CC Particle Systems II echoed the black solid under the
+/// fireworks and blacked out the white page). Fill (red) then Echo: the echoes are red.
+#[test]
+fn time_effects_see_the_effects_before_them() {
+    let (mut p, cid) = scene(Some(("ec.generate.fill", &[])));
+    let spec = effectcraft_effects::find("ec.time.echo").unwrap();
+    let mut next = p.next_id;
+    let mut g = effectcraft_effects::instantiate(spec, &mut Ids(&mut next), spec.name, [200.0, 100.0]);
+    g.prop_mut("numberOfEchoes").unwrap().value = Value::Scalar(0.0);
+    p.next_id = next;
+    p.comp_mut(cid).unwrap().layers[0].props.sub_mut("effects").unwrap().children.push(g.into());
+    let c = render(&p, cid, 1.5, None).get(100, 50);
+    assert!(c[0] > 0.99 && c[1] < 0.01 && c[2] < 0.01 && c[3] > 0.99, "{c:?}");
+}
+
 #[test]
 fn time_difference_of_static_layer_is_black() {
     let mut p = Project::default();