diff --git a/src/scene.cc b/src/scene.cc
index dd304f5..085e881 100644
--- a/src/scene.cc
+++ b/src/scene.cc
@@ -94,10 +94,6 @@ void
 Scene::render()
 {
     pixels = new Color[width * height];
-    if (pixels == NULL) {
-        // TODO: Print an error.
-        return;
-    }
 
     Ray primary_ray;
     Vector3 o, d;
@@ -173,6 +169,20 @@ Scene::trace_ray(const Ray &ray, const int depth)
         return Color::Black;
     }
 
-    // TODO: Lighting.
-    return intersected_shape->get_material().get_color();
+    Color out_color = intersected_shape->get_material().get_color();
+
+    Vector3 intersection = ray.parameterize(nearest_t);
+    Vector3 normal = intersected_shape->compute_normal(intersection);
+
+    for (Light *l : lights) {
+        Vector3 light_direction = intersection - l->get_origin();
+        light_direction.normalize();
+
+        float ldotn = light_direction.dot(normal);
+        out_color.red *= ((ldotn >= 0.0) ? ldotn : 0.0) * l->get_intensity();
+        out_color.green *= ((ldotn >= 0.0) ? ldotn : 0.0) * l->get_intensity();
+        out_color.blue *= ((ldotn >= 0.0) ? ldotn : 0.0) * l->get_intensity();
+    }
+
+    return out_color;
 }