diff --git a/src/mesh.rs b/src/mesh.rs
index 65c9fa1..579070c 100644
--- a/src/mesh.rs
+++ b/src/mesh.rs
@@ -70,7 +70,7 @@ impl Mesh {
         self.triangulation.vertex(vertex.handle).as_ref().dot
     }
 
-    pub fn vertex(&self, dot: DotIndex) -> VertexIndex {
+    pub fn vertex(&self, dot: FixedDotIndex) -> VertexIndex {
         self.dot_to_vertex[dot.node_index().index()].unwrap()
     }
 
diff --git a/src/router.rs b/src/router.rs
index 0294ea2..1c22ec7 100644
--- a/src/router.rs
+++ b/src/router.rs
@@ -48,7 +48,9 @@ impl<'a, RO: RouterObserver> AstarStrategy<&Mesh, u64> for RouterAstarStrategy<'
         self.tracer.rework_path(&mut self.trace, &new_path, 5.0);
         self.observer.on_rework(&self.tracer, &self.trace);
 
-        self.tracer.finish(&mut self.trace, self.to, 5.0).is_ok()
+        self.tracer
+            .finish(&mut self.trace, self.tracer.mesh.dot(self.to), 5.0)
+            .is_ok()
     }
 
     fn edge_cost(&mut self, edge: MeshEdgeReference) -> Option<u64> {
@@ -94,17 +96,12 @@ impl Router {
         mesh.triangulate(&self.layout)?;
 
         let mut tracer = self.tracer(&mesh);
-        let trace = tracer.start(mesh.vertex(DotIndex::Fixed(from)));
+        let trace = tracer.start(from);
 
         let (_cost, _path) = astar(
             &mesh,
-            mesh.vertex(DotIndex::Fixed(from)),
-            &mut RouterAstarStrategy::new(
-                tracer,
-                trace,
-                mesh.vertex(DotIndex::Fixed(to)),
-                observer,
-            ),
+            mesh.vertex(from),
+            &mut RouterAstarStrategy::new(tracer, trace, mesh.vertex(to), observer),
         )
         .unwrap(); // TODO.
 
diff --git a/src/tracer.rs b/src/tracer.rs
index 6b20ce1..e721717 100644
--- a/src/tracer.rs
+++ b/src/tracer.rs
@@ -29,18 +29,15 @@ impl<'a> Tracer<'a> {
         }
     }
 
-    pub fn start(&mut self, from: VertexIndex) -> Trace {
+    pub fn start(&mut self, from: FixedDotIndex) -> Trace {
         Trace {
-            path: vec![from],
-            head: Head::from(BareHead {
-                dot: self.mesh.dot(from),
-            }),
+            path: vec![self.mesh.vertex(from)],
+            head: BareHead { dot: from }.into(),
         }
     }
 
-    pub fn finish(&mut self, trace: &mut Trace, into: VertexIndex, width: f64) -> Result<(), ()> {
-        let into_dot = self.mesh.dot(into);
-        self.draw().finish_in_dot(trace.head, into_dot, width)
+    pub fn finish(&mut self, trace: &mut Trace, into: FixedDotIndex, width: f64) -> Result<(), ()> {
+        self.draw().finish_in_dot(trace.head, into, width)
     }
 
     #[debug_ensures(ret.is_ok() -> trace.path.len() == path.len())]