diff --git a/eth/main.cpp b/eth/main.cpp
index 73adddf1e..24520d8c4 100644
--- a/eth/main.cpp
+++ b/eth/main.cpp
@@ -266,8 +266,7 @@ enum class OperationMode
 {
 	Node,
 	Import,
-	Export,
-	Rescue
+	Export
 };
 
 enum class Format
@@ -1085,7 +1084,7 @@ int main(int argc, char** argv)
 #endif
 	string jsonAdmin;
 	bool upnp = true;
-	WithExisting killChain = WithExisting::Trust;
+	WithExisting withExisting = WithExisting::Trust;
 	bool jit = false;
 	string sentinel;
 
@@ -1252,11 +1251,11 @@ int main(int argc, char** argv)
 				return -1;
 			}
 		else if (arg == "-K" || arg == "--kill-blockchain" || arg == "--kill")
-			killChain = WithExisting::Kill;
+			withExisting = WithExisting::Kill;
 		else if (arg == "-R" || arg == "--rebuild")
-			killChain = WithExisting::Verify;
+			withExisting = WithExisting::Verify;
 		else if (arg == "-R" || arg == "--rescue")
-			mode = OperationMode::Rescue;
+			withExisting = WithExisting::Rescue;
 		else if ((arg == "-c" || arg == "--client-name") && i + 1 < argc)
 		{
 			if (arg == "-c")
@@ -1534,7 +1533,7 @@ int main(int argc, char** argv)
 	dev::WebThreeDirect web3(
 		WebThreeDirect::composeClientVersion("++eth", clientName),
 		dbPath,
-		killChain,
+		withExisting,
 		nodeMode == NodeMode::Full ? set<string>{"eth"/*, "shh"*/} : set<string>(),
 		netPrefs,
 		&nodesState);
@@ -1556,12 +1555,6 @@ int main(int argc, char** argv)
 		}
 	};
 
-	if (mode == OperationMode::Rescue)
-	{
-		web3.ethereum()->rescue();
-		exit(0);
-	}
-
 	if (mode == OperationMode::Export)
 	{
 		ofstream fout(filename, std::ofstream::binary);
diff --git a/libdevcore/Common.h b/libdevcore/Common.h
index edd14f4a5..303512e57 100644
--- a/libdevcore/Common.h
+++ b/libdevcore/Common.h
@@ -189,7 +189,7 @@ private:
 
 /// Scope guard for invariant check in a class derived from HasInvariants.
 #if ETH_DEBUG
-#define DEV_INVARIANT_CHECK { ::dev::InvariantChecker __dev_invariantCheck(this, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__); }
+#define DEV_INVARIANT_CHECK ::dev::InvariantChecker __dev_invariantCheck(this, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__)
 #else
 #define DEV_INVARIANT_CHECK (void)0;
 #endif
@@ -240,6 +240,7 @@ enum class WithExisting: int
 {
 	Trust = 0,
 	Verify,
+	Rescue,
 	Kill
 };
 
diff --git a/libdevcore/FixedHash.h b/libdevcore/FixedHash.h
index a9922063a..3127b349a 100644
--- a/libdevcore/FixedHash.h
+++ b/libdevcore/FixedHash.h
@@ -106,6 +106,8 @@ public:
 	FixedHash& operator&=(FixedHash const& _c) { for (unsigned i = 0; i < N; ++i) m_data[i] &= _c.m_data[i]; return *this; }
 	FixedHash operator&(FixedHash const& _c) const { return FixedHash(*this) &= _c; }
 	FixedHash operator~() const { FixedHash ret; for (unsigned i = 0; i < N; ++i) ret[i] = ~m_data[i]; return ret; }
+
+	// Big-endian increment.
 	FixedHash& operator++() { for (unsigned i = size; i > 0 && !++m_data[--i]; ) {} return *this; }
 
 	/// @returns true if all one-bits in @a _c are set in this object.
diff --git a/libdevcore/Guards.h b/libdevcore/Guards.h
index 2d3eced32..44d5969e4 100644
--- a/libdevcore/Guards.h
+++ b/libdevcore/Guards.h
@@ -95,7 +95,7 @@ using SpinGuard = std::lock_guard<SpinLock>;
  * Mutex m;
  * int d;
  * ...
- * ETH_(m)
+ * ETH_GUARDED(m)
  * {
  *   for (auto d = 50; d > 25; --d)
  *     foo(d);
diff --git a/libethereum/Client.cpp b/libethereum/Client.cpp
index 2295904cc..054cd1c9b 100644
--- a/libethereum/Client.cpp
+++ b/libethereum/Client.cpp
@@ -90,6 +90,9 @@ Client::Client(p2p::Host* _extNet, std::shared_ptr<GasPricer> _gp, std::string c
 	m_preMine(m_stateDB, BaseState::CanonGenesis),
 	m_postMine(m_stateDB)
 {
+	if (_forceAction == WithExisting::Rescue)
+		m_bc.rescue(m_stateDB);
+
 	m_lastGetWork = std::chrono::system_clock::now() - chrono::seconds(30);
 	m_tqReady = m_tq.onReady([=](){ this->onTransactionQueueReady(); });	// TODO: should read m_tq->onReady(thisThread, syncTransactionQueue);
 	m_bqReady = m_bq.onReady([=](){ this->onBlockQueueReady(); });			// TODO: should read m_bq->onReady(thisThread, syncBlockQueue);
diff --git a/libethereum/Client.h b/libethereum/Client.h
index 5124f3778..fac54b010 100644
--- a/libethereum/Client.h
+++ b/libethereum/Client.h
@@ -219,8 +219,6 @@ public:
 	void setExtraData(bytes const& _extraData) { m_extraData = _extraData; }
 	/// Rewind to a prior head.
 	void rewind(unsigned _n) { m_bc.rewind(_n); }
-	/// Rescue the chain.
-	void rescue() { stopWorking(); m_bc.rescue(m_stateDB); }
 
 protected:
 	/// InterfaceStub methods