diff --git a/internal/experimental/k8s/ate/client.go b/internal/experimental/k8s/ate/client.go
index 8f36a17..4237285 100644
--- a/internal/experimental/k8s/ate/client.go
+++ b/internal/experimental/k8s/ate/client.go
@@ -69,6 +69,19 @@ func (c *Client) CreateActor(ctx context.Context, id string) (*ateapipb.CreateAc
 	return resp, nil
 }
 
+// ResumeActor resumes the actor, scheduling it onto a worker. The returned
+// actor carries the worker IP once it is running.
+func (c *Client) ResumeActor(ctx context.Context, id string) (*ateapipb.ResumeActorResponse, error) {
+	client := ateapipb.NewControlClient(c.conn)
+	resp, err := client.ResumeActor(ctx, &ateapipb.ResumeActorRequest{
+		ActorId: id,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("error when calling Control.ResumeActor: %w", err)
+	}
+	return resp, nil
+}
+
 // SuspendActor suspends the actor.
 func (c *Client) SuspendActor(ctx context.Context, id string) (*ateapipb.SuspendActorResponse, error) {
 	client := ateapipb.NewControlClient(c.conn)
diff --git a/internal/harness/substrate.go b/internal/harness/substrate.go
index 9dafb9c..9126ea4 100644
--- a/internal/harness/substrate.go
+++ b/internal/harness/substrate.go
@@ -16,6 +16,7 @@ package harness
 
 import (
 	"context"
+	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -24,7 +25,10 @@ import (
 	"time"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/credentials/insecure"
+	"google.golang.org/grpc/status"
 
 	"github.com/google/ax/internal/experimental/k8s/ate"
 	"github.com/google/ax/proto"
@@ -49,7 +53,8 @@ func NewSubstrateHarness(endpoint string, namespace string, template string, por
 	if template == "" {
 		template = "ax-harness-template"
 	}
-	client, err := ate.NewClient(namespace, template, endpoint)
+	controlCreds := grpc.WithTransportCredentials(credentials.NewTLS(&tls.Config{InsecureSkipVerify: true}))
+	client, err := ate.NewClient(namespace, template, endpoint, controlCreds)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create ATE client: %w", err)
 	}
@@ -69,11 +74,18 @@ func (h *SubstrateHarness) Start(ctx context.Context, conversationID string) (Ex
 		return nil, errors.New("SubstrateHarness needs valid conversationID")
 	}
 
-	resp, err := h.ateClient.CreateActor(ctx, conversationID)
-	if err != nil {
+	// CreateActor is idempotent here: on follow-up turns the actor was created
+	// (and suspended) on a previous turn, so AlreadyExists is expected and fine.
+	if _, err := h.ateClient.CreateActor(ctx, conversationID); err != nil && status.Code(err) != codes.AlreadyExists {
 		return nil, fmt.Errorf("failed to create substrate actor %s: %w", conversationID, err)
 	}
-	actor := resp.Actor
+
+	// Resume the actor so it is scheduled onto a worker and gets a routable IP.
+	resumeResp, err := h.ateClient.ResumeActor(ctx, conversationID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to resume substrate actor %s: %w", conversationID, err)
+	}
+	actor := resumeResp.Actor
 	if actor == nil {
 		return nil, fmt.Errorf("received nil actor in response for %s", conversationID)
 	}
diff --git a/internal/manifests/README.md b/internal/manifests/README.md
index d44ed46..acb6cb2 100644
--- a/internal/manifests/README.md
+++ b/internal/manifests/README.md
@@ -41,6 +41,12 @@ This command will:
 - Create the `ax` namespace.
 - Create the `WorkerPool` and `ActorTemplate` for the AX harness.
 - Create the `ax-server` `ReplicaSet` (the controller front-end).
+- Create the `ax-server-config` `ConfigMap` that tells the `ax-server` which
+  harnesses to serve (mounted at `/etc/ax/ax.yaml`).
+
+The harness registry lives in that `ConfigMap`. By default it registers a
+substrate harness (`hello-world`) backed by the `ax-harness-template`, marked as
+the default via `harnesses.default`.
 
 Wait until the template is ready:
 ```bash
@@ -70,9 +76,9 @@ Conversation: fb344a18-3720-4c4f-8a6e-2ce34db975b3
 
 ⏺ hello
 
-Hello world
+hello world
 ```
-*The request is served directly by the `ax-server`.*
+*The request is served by the harness actor running on Substrate.*
 
 ## 🧹 How to Uninstall