diff --git a/README.md b/README.md
index 1dff83d..fbb47a9 100644
--- a/README.md
+++ b/README.md
@@ -216,7 +216,9 @@ korg campaign --tui --prompt "Refactor the auth layer to use JWTs"
 # Web cockpit at localhost:8080
 korg campaign --web --prompt "Optimize the database connection pool"
 
-# Pure autonomous goal mode (--goal is a top-level flag)
+# Pure autonomous goal mode (--goal is a top-level flag). Each persona works in
+# its own git worktree and runs a real `cargo check`, so on a large repo a cold
+# run takes minutes; `--speculative` pre-warms a shared target dir.
 korg --goal "Write and validate a full test suite for src/parser.rs"
 
 # Run the full multi-persona swarm on a REAL local model — every persona
@@ -232,7 +234,10 @@ korg --preview "Refactor the main event loop"
 ### Rewind & Verify
 
 ```bash
-# Rewind the capability journal to a specific ledger sequence point
+# Rewind the capability journal (.korg/capability_journal.json) to a prior
+# sequence point. It is populated by campaigns (`korg --goal`, `korg campaign`);
+# on a fresh checkout there is nothing to rewind yet — `korg demo` shows the
+# full rewind flow in a self-contained sandbox.
 korg rewind --seq 4
 
 # Drive the honest pipeline on a fixture and emit a verifiable ledger
diff --git a/crates/korg-runtime/src/harness.rs b/crates/korg-runtime/src/harness.rs
index 40e1881..074fa25 100644
--- a/crates/korg-runtime/src/harness.rs
+++ b/crates/korg-runtime/src/harness.rs
@@ -243,6 +243,16 @@ impl SingleWorkerHarness {
         }
 
         let branch_name = format!("korg-branch-{}", routing_id);
+
+        // A previous run that was interrupted (Ctrl-C, timeout) leaves its
+        // worktree registered in git even though the directory was removed
+        // above; `worktree add -B` then refuses to reset the branch it still
+        // holds. Pruning drops registrations whose directories are gone.
+        let _ = tokio::process::Command::new("git")
+            .args(&["worktree", "prune"])
+            .output()
+            .await;
+
         eprintln!(
             "[Harness] Spinning up physical worktree at {:?} from commit {} (branch: {})",
             worktree_path, snapshot_ref, branch_name
diff --git a/demo.gif b/demo.gif
index e9eb03a..3f3ab39 100644
Binary files a/demo.gif and b/demo.gif differ
diff --git a/demo.mp4 b/demo.mp4
index 0ce3078..7db2e38 100644
Binary files a/demo.mp4 and b/demo.mp4 differ
diff --git a/demo.tape b/demo.tape
index d880a7d..fcbbae0 100644
--- a/demo.tape
+++ b/demo.tape
@@ -28,6 +28,12 @@ Set PlaybackSpeed 1
 Hide
 Type "export PATH=$PWD/target/release:$PATH"
 Enter
+# Seed a real capability journal for step 5: run an actual (hermetic,
+# deterministic-provider) swarm campaign on a scratch copy of the fixture repo.
+# This takes ~1 min and is hidden only to keep the GIF short.
+Type "W=$(mktemp -d) && cp -r fixtures/honest-demo-repo/. $W && git -C $W init -q && git -C $W add -A && git -C $W -c user.email=demo@korg -c user.name=demo commit -qm init && (cd $W && korg --goal 'Fix the add function in src/lib.rs so it adds' >/dev/null 2>&1)"
+Enter
+Sleep 120s
 Type "clear"
 Enter
 Show
@@ -66,10 +72,10 @@ Sleep 3s
 Ctrl+L
 
 # ── 5. Real reversible rewind of the capability journal ───────────────────────
-# Operates on this repo's real .korg/execution_journal.jsonl — a real
-# hash-chained truncation + re-seal, not a scripted message.
+# Operates on the real .korg/capability_journal.json the hidden setup's campaign
+# wrote — a real hash-chained truncation + LedgerRewind seal, not a scripted message.
 Sleep 400ms
-Type "korg rewind --seq 1"
+Type "cd $W && korg rewind --seq 4"
 Enter
 Sleep 4s
 Ctrl+L
@@ -83,11 +89,11 @@ Enter
 Sleep 600ms
 Type "echo ''"
 Enter
-Type "echo 'A tamper-evident ledger for AI agent cognition — no trust in the tool.'"
+Type "echo 'A tamper-evident ledger for AI agent cognition. No trust in the tool.'"
 Enter
 Sleep 600ms
 Type "echo ''"
 Enter
-Type "echo 'cargo install korg   →   github.com/New1Direction/korg'"
+Type "echo 'git clone github.com/New1Direction/korg && cargo build --release'"
 Enter
 Sleep 4s
diff --git a/demo.webp b/demo.webp
index 3a0c242..ccaf872 100644
Binary files a/demo.webp and b/demo.webp differ
diff --git a/korg.toml b/korg.toml
index 589de0a..d865d76 100644
--- a/korg.toml
+++ b/korg.toml
@@ -1,5 +1,7 @@
 # korg Swarm cognitive configuration surface
-default_llm = "ollama"
+# Hermetic by default (no network, no model). Pass `--provider ollama` or set
+# default_llm = "ollama" here to run every persona on a live local model.
+default_llm = "deterministic"
 default_model = "llama3-70b-monochrome"
 
 [ollama]
diff --git a/src/main.rs b/src/main.rs
index 164d62a..aba9112 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -822,6 +822,14 @@ async fn main() -> Result<()> {
         Commands::Rewind { seq } => {
             let mut journal = korg_registry::CapabilityJournal::default_journal();
             let prev_count = journal.events.len();
+            if journal.events.is_empty() {
+                eprintln!(
+                    "\n\x1b[38;2;255;0;180m❌ Nothing to rewind: no events in .korg/capability_journal.json yet.\x1b[0m\n   \
+                     Record some first, e.g. `korg --goal \"<task>\"`, or run `korg demo` for a\n   \
+                     self-contained rewind walkthrough."
+                );
+                std::process::exit(1);
+            }
             match journal.rewind_with_seal(seq, "korg:cli", "operator rewind") {
                 Ok(()) => {
                     let green = "\x1b[38;2;0;255;128m";
@@ -855,7 +863,7 @@ async fn main() -> Result<()> {
                     let pink = "\x1b[38;2;255;0;180m";
                     let reset = "\x1b[0m";
                     eprintln!("\n{}❌ Rewind failed: {}{}", pink, e, reset);
-                    return Err(anyhow::anyhow!("Rewind failed: {}", e));
+                    std::process::exit(1);
                 }
             }
         }