diff --git a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoMap.java b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoMap.java
index 7833d267e66..e68f1ba31a5 100644
--- a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoMap.java
+++ b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoMap.java
@@ -75,6 +75,11 @@ public long lastUpdate() {
     return undoLog.get(undoLog.size() - 1).level;
   }
 
+
+  /**
+   * Has the map been changed
+   * @return true if there are any undo entries in the log
+   */
   public boolean updated() {
     return !undoLog.isEmpty();
   }
diff --git a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoNavigableMap.java b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoNavigableMap.java
index 2edf58cb01d..f9c54c42412 100644
--- a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoNavigableMap.java
+++ b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoNavigableMap.java
@@ -41,6 +41,13 @@ public UndoNavigableMap(final NavigableMap<K, V> delegate) {
     super(delegate);
   }
 
+  /**
+   * Create an undo navigable map backed by a specific map.
+   * @param map The map storing the current state
+   * @return an undoable map
+   * @param <K> the key type
+   * @param <V> the value type
+   */
   public static <K, V> UndoNavigableMap<K, V> of(final NavigableMap<K, V> map) {
     return new UndoNavigableMap<>(map);
   }
diff --git a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoScalar.java b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoScalar.java
index bfa79a9ec89..0e3356c379b 100644
--- a/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoScalar.java
+++ b/evm/src/main/java/org/hyperledger/besu/collections/undo/UndoScalar.java
@@ -19,6 +19,11 @@
 import java.util.List;
 import java.util.Objects;
 
+/**
+ * An undoable value that tracks the value across time.
+ *
+ * @param <T> The type of the scaler.
+ */
 public class UndoScalar<T> implements Undoable {
   record UndoEntry<T>(T value, long level) {
     UndoEntry(final T value) {
@@ -29,10 +34,22 @@ record UndoEntry<T>(T value, long level) {
   T value;
   final List<UndoEntry<T>> undoLog;
 
+  /**
+   * Create an undoable scalar with an initial value
+   *
+   * @param value the initial value
+   * @return the undoable scalar
+   * @param <T> the type of the scalar
+   */
   public static <T> UndoScalar<T> of(final T value) {
     return new UndoScalar<>(value);
   }
 
+  /**
+   * Create an undo scalar with an initial value
+   *
+   * @param value the initial value
+   */
   public UndoScalar(final T value) {
     undoLog = new ArrayList<>();
     this.value = value;
@@ -43,14 +60,29 @@ public long lastUpdate() {
     return undoLog.isEmpty() ? 0L : undoLog.get(undoLog.size() - 1).level;
   }
 
+  /**
+   * Has this scalar had any change since the inital value
+   *
+   * @return true if there are any changes to undo
+   */
   public boolean updated() {
     return !undoLog.isEmpty();
   }
 
+  /**
+   * Get the current value of the scalar.
+   *
+   * @return the current value
+   */
   public T get() {
     return value;
   }
 
+  /**
+   * Set a new value in the scalar.
+   *
+   * @param value new value
+   */
   public void set(final T value) {
     if (!Objects.equals(this.value, value)) {
       undoLog.add(new UndoEntry<>(this.value));
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleAccount.java b/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleAccount.java
index 403c72d4b2c..755523e6b49 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleAccount.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleAccount.java
@@ -188,4 +188,20 @@ public Map<UInt256, UInt256> getUpdatedStorage() {
   public void becomeImmutable() {
     immutable = true;
   }
+
+  /**
+   * Commit this simple account entry to the parent.
+   *
+   * @return true if there was a parent account that was committed to
+   */
+  public boolean commit() {
+    if (parent instanceof SimpleAccount simpleAccount) {
+      simpleAccount.balance = balance;
+      simpleAccount.nonce = nonce;
+      simpleAccount.storage.putAll(storage);
+      return true;
+    } else {
+      return false;
+    }
+  }
 }
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleWorld.java b/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleWorld.java
index 6bc19ca0dae..404edf17025 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleWorld.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/fluent/SimpleWorld.java
@@ -66,6 +66,9 @@ public Account get(final Address address) {
 
   @Override
   public MutableAccount createAccount(final Address address, final long nonce, final Wei balance) {
+    if (getAccount(address) != null) {
+      throw new IllegalStateException("Cannot create an account when one already exists");
+    }
     SimpleAccount account = new SimpleAccount(address, nonce, balance);
     accounts.put(address, account);
     return account;
@@ -75,11 +78,23 @@ public MutableAccount createAccount(final Address address, final long nonce, fin
   public MutableAccount getAccount(final Address address) {
     if (accounts.containsKey(address)) {
       return accounts.get(address);
-    } else if (parent != null) {
-      return parent.getAccount(address);
-    } else {
+    }
+    if (parent == null) {
       return null;
     }
+    Account parentAccount = parent.getAccount(address);
+    if (parentAccount == null) {
+      return null;
+    }
+    SimpleAccount account =
+        new SimpleAccount(
+            parentAccount,
+            parentAccount.getAddress(),
+            parentAccount.getNonce(),
+            parentAccount.getBalance(),
+            parentAccount.getCode());
+    accounts.put(address, account);
+    return account;
   }
 
   @Override
@@ -107,11 +122,16 @@ public void revert() {
 
   @Override
   public void commit() {
-    parent.accounts.putAll(accounts);
+    accounts.forEach(
+        (address, account) -> {
+          if (!account.commit()) {
+            accounts.put(address, account);
+          }
+        });
   }
 
   @Override
   public Optional<WorldUpdater> parentUpdater() {
-    return Optional.empty();
+    return Optional.ofNullable(parent);
   }
 }
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/precompile/BigIntegerModularExponentiationPrecompiledContract.java b/evm/src/main/java/org/hyperledger/besu/evm/precompile/BigIntegerModularExponentiationPrecompiledContract.java
index 9f33b45b2ff..42e3279c727 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/precompile/BigIntegerModularExponentiationPrecompiledContract.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/precompile/BigIntegerModularExponentiationPrecompiledContract.java
@@ -126,6 +126,10 @@ public PrecompileContractResult computePrecompile(
    * Compute default precompile contract.
    *
    * @param input the input
+   * @param base base of the exponent
+   * @param exp the exponent
+   * @param mod the modulus
+   * @param modulusLength the length of the modulus, in bytes
    * @return the precompile contract result
    */
   @Nonnull
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledAccount.java b/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledAccount.java
index ff02e0d421e..9d2bd060d41 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledAccount.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledAccount.java
@@ -226,6 +226,10 @@ public boolean hasCode() {
     return !code.get().isEmpty();
   }
 
+  /**
+   * Mark the account as deleted/not deleted
+   * @param accountDeleted delete or don't delete this account.
+   */
   public void setDeleted(final boolean accountDeleted) {
     if (immutable) {
       throw new ModificationNotAllowedException();
@@ -233,6 +237,10 @@ public void setDeleted(final boolean accountDeleted) {
     deleted.set(accountDeleted);
   }
 
+  /**
+   * Is the account marked as deleted?
+   * @return is the account deleted?
+   */
   public Boolean getDeleted() {
     return deleted.get();
   }
@@ -368,6 +376,7 @@ public void undo(final long mark) {
     updatedStorage.undo(mark);
   }
 
+  /** Commit this journaled account entry to the parent, if it is not a journaled account. */
   public void commit() {
     if (!(account instanceof JournaledAccount)) {
       if (nonce.updated()) {
diff --git a/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledUpdater.java b/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledUpdater.java
index 59f81faa1d1..85acf5ed204 100644
--- a/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledUpdater.java
+++ b/evm/src/main/java/org/hyperledger/besu/evm/worldstate/JournaledUpdater.java
@@ -64,6 +64,12 @@ public JournaledUpdater(final WorldUpdater world) {
     undoMark = accounts.mark();
   }
 
+  /**
+   * Get an account suitable for mutation. Defer to parent if not tracked locally.
+   *
+   * @param address the account at the address, for mutaton.
+   * @return the mutable account
+   */
   protected MutableAccount getForMutation(final Address address) {
     final JournaledAccount wrappedTracker = accounts.get(address);
     if (wrappedTracker != null) {
@@ -83,6 +89,9 @@ public Collection<Address> getDeletedAccountAddresses() {
     return new ArrayList<>(deleted);
   }
 
+  /**
+   * Remove all changes done by this layer. Rollback to the state prior to the updater's changes.
+   */
   protected void reset() {
     accounts.values().forEach(a -> a.undo(undoMark));
     accounts.undo(undoMark);