diff --git a/ethchain/closure.go b/ethchain/closure.go
index 3d15f2a990..de21964996 100644
--- a/ethchain/closure.go
+++ b/ethchain/closure.go
@@ -52,7 +52,7 @@ func (c *Closure) Get(x *big.Int) *ethutil.Value {
 }
 
 func (c *Closure) Gets(x, y *big.Int) *ethutil.Value {
-	if x.Int64() > int64(len(c.Script)) || y.Int64() > int64(len(c.Script)) {
+	if x.Int64() >= int64(len(c.Script)) || y.Int64() >= int64(len(c.Script)) {
 		return ethutil.NewValue(0)
 	}
 
@@ -69,7 +69,7 @@ func (c *Closure) Address() []byte {
 	return c.object.Address()
 }
 
-type DebugHook func(op OpCode)
+type DebugHook func(op OpCode, mem *Memory, stack *Stack)
 
 func (c *Closure) Call(vm *Vm, args []byte, hook DebugHook) []byte {
 	c.Args = args
diff --git a/ethchain/contract.go b/ethchain/contract.go
index e99e413f7a..af348667c3 100644
--- a/ethchain/contract.go
+++ b/ethchain/contract.go
@@ -69,6 +69,14 @@ func (c *Contract) Address() []byte {
 	return c.address
 }
 
+func (c *Contract) Script() []byte {
+	return c.script
+}
+
+func (c *Contract) Init() []byte {
+	return c.initScript
+}
+
 func (c *Contract) RlpEncode() []byte {
 	return ethutil.Encode([]interface{}{c.Amount, c.Nonce, c.state.trie.Root, c.script, c.initScript})
 }
diff --git a/ethchain/stack.go b/ethchain/stack.go
index d475f2f8e0..2aca0a3500 100644
--- a/ethchain/stack.go
+++ b/ethchain/stack.go
@@ -173,6 +173,10 @@ func NewStack() *Stack {
 	return &Stack{}
 }
 
+func (st *Stack) Data() []*big.Int {
+	return st.data
+}
+
 func (st *Stack) Pop() *big.Int {
 	str := st.data[len(st.data)-1]
 
@@ -246,6 +250,10 @@ func (m *Memory) Len() int {
 	return len(m.store)
 }
 
+func (m *Memory) Data() []byte {
+	return m.store
+}
+
 func (m *Memory) Print() {
 	fmt.Printf("### mem %d bytes ###\n", len(m.store))
 	if len(m.store) > 0 {
diff --git a/ethchain/state_manager.go b/ethchain/state_manager.go
index 111d2c019e..549d599594 100644
--- a/ethchain/state_manager.go
+++ b/ethchain/state_manager.go
@@ -318,14 +318,14 @@ func (sm *StateManager) ProcessContract(contract *Contract, tx *Transaction, blo
 	caller := sm.procState.GetAccount(tx.Sender())
 	closure := NewClosure(caller, contract, contract.script, sm.procState, tx.Gas, tx.Value)
 	vm := NewVm(sm.procState, RuntimeVars{
-		origin:      caller.Address(),
-		blockNumber: block.BlockInfo().Number,
-		prevHash:    block.PrevHash,
-		coinbase:    block.Coinbase,
-		time:        block.Time,
-		diff:        block.Difficulty,
+		Origin:      caller.Address(),
+		BlockNumber: block.BlockInfo().Number,
+		PrevHash:    block.PrevHash,
+		Coinbase:    block.Coinbase,
+		Time:        block.Time,
+		Diff:        block.Difficulty,
 		// XXX Tx data? Could be just an argument to the closure instead
-		txData: nil,
+		TxData: nil,
 	})
 	closure.Call(vm, nil, nil)
 
diff --git a/ethchain/vm.go b/ethchain/vm.go
index dce972cc73..fbe0d0439b 100644
--- a/ethchain/vm.go
+++ b/ethchain/vm.go
@@ -2,7 +2,7 @@ package ethchain
 
 import (
 	_ "bytes"
-	_ "fmt"
+	"fmt"
 	"github.com/ethereum/eth-go/ethutil"
 	_ "github.com/obscuren/secp256k1-go"
 	_ "math"
@@ -33,13 +33,13 @@ type Vm struct {
 }
 
 type RuntimeVars struct {
-	origin      []byte
-	blockNumber uint64
-	prevHash    []byte
-	coinbase    []byte
-	time        int64
-	diff        *big.Int
-	txData      []string
+	Origin      []byte
+	BlockNumber uint64
+	PrevHash    []byte
+	Coinbase    []byte
+	Time        int64
+	Diff        *big.Int
+	TxData      []string
 }
 
 func NewVm(state *State, vars RuntimeVars) *Vm {
@@ -65,9 +65,11 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 	// The base for all big integer arithmetic
 	base := new(big.Int)
 
-	if ethutil.Config.Debug {
-		ethutil.Config.Log.Debugf("#   op\n")
-	}
+	/*
+		if ethutil.Config.Debug {
+			ethutil.Config.Log.Debugf("#   op\n")
+		}
+	*/
 
 	for {
 		step++
@@ -75,9 +77,11 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		val := closure.Get(pc)
 		// Get the opcode (it must be an opcode!)
 		op := OpCode(val.Uint())
-		if ethutil.Config.Debug {
-			ethutil.Config.Log.Debugf("%-3d %-4s", pc, op.String())
-		}
+		/*
+			if ethutil.Config.Debug {
+				ethutil.Config.Log.Debugf("%-3d %-4s", pc, op.String())
+			}
+		*/
 
 		// TODO Get each instruction cost properly
 		gas := new(big.Int)
@@ -270,7 +274,7 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		case oBALANCE:
 			stack.Push(closure.Value)
 		case oORIGIN:
-			stack.Push(ethutil.BigD(vm.vars.origin))
+			stack.Push(ethutil.BigD(vm.vars.Origin))
 		case oCALLER:
 			stack.Push(ethutil.BigD(closure.Callee().Address()))
 		case oCALLVALUE:
@@ -286,15 +290,15 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 
 		// 0x40 range
 		case oPREVHASH:
-			stack.Push(ethutil.BigD(vm.vars.prevHash))
+			stack.Push(ethutil.BigD(vm.vars.PrevHash))
 		case oCOINBASE:
-			stack.Push(ethutil.BigD(vm.vars.coinbase))
+			stack.Push(ethutil.BigD(vm.vars.Coinbase))
 		case oTIMESTAMP:
-			stack.Push(big.NewInt(vm.vars.time))
+			stack.Push(big.NewInt(vm.vars.Time))
 		case oNUMBER:
-			stack.Push(big.NewInt(int64(vm.vars.blockNumber)))
+			stack.Push(big.NewInt(int64(vm.vars.BlockNumber)))
 		case oDIFFICULTY:
-			stack.Push(vm.vars.diff)
+			stack.Push(vm.vars.Diff)
 		case oGASLIMIT:
 			// TODO
 
@@ -406,7 +410,59 @@ func (vm *Vm) RunClosure(closure *Closure, hook DebugHook) []byte {
 		pc.Add(pc, ethutil.Big1)
 
 		if hook != nil {
-			hook(op)
+			hook(op, mem, stack)
+		}
+	}
+}
+
+func Disassemble(script []byte) (asm []string) {
+	pc := new(big.Int)
+	for {
+		if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 {
+			return
+		}
+
+		// Get the memory location of pc
+		val := script[pc.Int64()]
+		// Get the opcode (it must be an opcode!)
+		op := OpCode(val)
+
+		asm = append(asm, fmt.Sprintf("%v", op))
+
+		switch op {
+		case oPUSH: // Push PC+1 on to the stack
+			pc.Add(pc, ethutil.Big1)
+			data := script[pc.Int64() : pc.Int64()+32]
+			val := ethutil.BigD(data)
+
+			var b []byte
+			if val.Int64() == 0 {
+				b = []byte{0}
+			} else {
+				b = val.Bytes()
+			}
+
+			asm = append(asm, fmt.Sprintf("0x%x", b))
+
+			pc.Add(pc, big.NewInt(31))
+		case oPUSH20:
+			pc.Add(pc, ethutil.Big1)
+			data := script[pc.Int64() : pc.Int64()+20]
+			val := ethutil.BigD(data)
+			var b []byte
+			if val.Int64() == 0 {
+				b = []byte{0}
+			} else {
+				b = val.Bytes()
+			}
+
+			asm = append(asm, fmt.Sprintf("0x%x", b))
+
+			pc.Add(pc, big.NewInt(19))
 		}
+
+		pc.Add(pc, ethutil.Big1)
 	}
+
+	return
 }
diff --git a/ethchain/vm_test.go b/ethchain/vm_test.go
index 5a1419c0f9..a0add95328 100644
--- a/ethchain/vm_test.go
+++ b/ethchain/vm_test.go
@@ -130,14 +130,29 @@ func TestRun4(t *testing.T) {
 	callerClosure := NewClosure(account, c, c.script, state, big.NewInt(1000000000), new(big.Int))
 
 	vm := NewVm(state, RuntimeVars{
-		origin:      account.Address(),
-		blockNumber: 1,
-		prevHash:    ethutil.FromHex("5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6"),
-		coinbase:    ethutil.FromHex("2adc25665018aa1fe0e6bc666dac8fc2697ff9ba"),
-		time:        1,
-		diff:        big.NewInt(256),
+		Origin:      account.Address(),
+		BlockNumber: 1,
+		PrevHash:    ethutil.FromHex("5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6"),
+		Coinbase:    ethutil.FromHex("2adc25665018aa1fe0e6bc666dac8fc2697ff9ba"),
+		Time:        1,
+		Diff:        big.NewInt(256),
 		// XXX Tx data? Could be just an argument to the closure instead
-		txData: nil,
+		TxData: nil,
 	})
 	callerClosure.Call(vm, nil, nil)
 }
+
+func TestRun5(t *testing.T) {
+	ethutil.ReadConfig("")
+
+	asm, _ := mutan.Compile(strings.NewReader(`
+		int32 a = 10
+		int32 b = 20
+		if a > b {
+			int32 c = this.caller()
+		}
+		exit()
+	`), false)
+	script := ethutil.Assemble(asm...)
+	fmt.Println(Disassemble(script))
+}