diff --git a/bootstrap/pkg/ast/ast.go b/bootstrap/pkg/ast/ast.go
index 8092694..7c79f38 100644
--- a/bootstrap/pkg/ast/ast.go
+++ b/bootstrap/pkg/ast/ast.go
@@ -63,7 +63,7 @@ func (s *Source) GetPos(start, end int) *string {
 }
 func (s *Source) GetLine(linenum int) string {
 	lines := strings.Split(strings.Join(*s.Buffer, ""), "\n")
-	if linenum > 0 && linenum < len(lines) {
+	if linenum > 0 && linenum <= len(lines) {
 		return lines[linenum-1]
 	}
 	return "----"
@@ -107,6 +107,21 @@ func (s *Source) LineNumberFor(pos int) int {
 	return result
 }
 
+var builtinSource *Source
+
+func GetBuiltinSource() *Source {
+	if builtinSource == nil {
+		buf := strings.Split("builtin", "")
+		lineindex := []int{len(buf) - 1}
+		builtinSource = &Source{
+			Buffer:    &buf,
+			Path:      "Builtin",
+			LineIndex: &lineindex,
+		}
+	}
+	return builtinSource
+}
+
 type Location struct {
 	start         int
 	end           int
@@ -125,7 +140,10 @@ func (l *Location) GetEnd() int {
 }
 
 func (l *Location) GetSource() *Source {
-	return &l.source
+	if l.IsKnownLocaiton() {
+		return &l.source
+	}
+	return GetBuiltinSource()
 }
 
 func (l *Location) IncStart(x int) {
diff --git a/bootstrap/pkg/core/builtins.go b/bootstrap/pkg/core/builtins.go
index f96a87d..e44ffa6 100644
--- a/bootstrap/pkg/core/builtins.go
+++ b/bootstrap/pkg/core/builtins.go
@@ -22,10 +22,10 @@ package core
 // the language which are implemented in Go
 var BUILTINS = map[string]NativeFunction{
 	"pr":      MakeNativeFn("pr", PrNativeFn),
-	"prn":     MakeNativeFn("pr", PrnNativeFn),
+	"prn":     MakeNativeFn("prn", PrnNativeFn),
 	"print":   MakeNativeFn("print", PrintNativeFn),
 	"println": MakeNativeFn("println", PrintlnNativeFn),
-	"require": MakeNativeFn("print", RequireNativeFn),
+	"require": MakeNativeFn("require", RequireNativeFn),
 	"hash":    MakeNativeFn("hash", HashNativeFn),
 }
 
diff --git a/bootstrap/pkg/core/call_stack.go b/bootstrap/pkg/core/call_stack.go
index 2d0ffc8..5490fa0 100644
--- a/bootstrap/pkg/core/call_stack.go
+++ b/bootstrap/pkg/core/call_stack.go
@@ -65,6 +65,10 @@ type CallStack struct {
 	count uint
 }
 
+func (f *Frame) String() string {
+	return fmt.Sprintf("<Frame: FN: %s, Count: %d Caller: \n%s\n>", f.Fn, f.Count, f.Caller)
+}
+
 func (c *CallStack) Count() uint {
 	return c.count
 }
@@ -158,7 +162,8 @@ func (c *CallStack) ToTraceBack() *TraceBack {
 		if item == nil {
 			break
 		}
-		tr = append(tr, &item.data)
+		// TODO: This doesn't seem efficient. Fix it.
+		tr = append([]*Frame{&item.data}, tr...)
 		item = item.prev
 	}
 
diff --git a/bootstrap/pkg/core/eval.go b/bootstrap/pkg/core/eval.go
index 87615cd..c746e26 100644
--- a/bootstrap/pkg/core/eval.go
+++ b/bootstrap/pkg/core/eval.go
@@ -82,19 +82,20 @@ func evalForm(rt *Runtime, scope IScope, form IExpr) (IExpr, IError) {
 			return MakeNil(MakeNodeFromExpr(form)), nil
 		default:
 			var expr *Binding
+			ns := scope.GetNS(rt)
 			if sym.IsNSQualified() {
 				// Whether a namespace with the given alias loaded or not
-				if !rt.CurrentNS().hasExternal(sym.GetNSPart()) {
+				if !ns.hasExternal(sym.GetNSPart()) {
 					return nil, MakeError(rt, sym,
 						fmt.Sprintf("Namespace '%s' is no loaded", sym.GetNSPart()),
 					)
 				}
 
-				expr = rt.CurrentNS().LookupGlobal(rt, sym)
+				expr = ns.LookupGlobal(rt, sym)
 				nsName = sym.GetNSPart()
 			} else {
 				expr = scope.Lookup(rt, symbolName)
-				nsName = rt.CurrentNS().GetName()
+				nsName = ns.GetName()
 			}
 
 			if expr == nil {
@@ -199,7 +200,7 @@ tco:
 			}
 
 			if rt.IsDebugMode() {
-				fmt.Printf("[DEBUG] Evaluating forms in NS: %s, Forms: %s\n", rt.CurrentNS().GetName(), forms)
+				fmt.Printf("[DEBUG] Evaluating forms in NS: %s, Forms: %s\n", scope.GetNS(rt).GetName(), forms)
 				fmt.Printf("[DEBUG] * State: I: %d, Exprs: %s\n", i, exprs)
 			}
 
@@ -394,7 +395,7 @@ tco:
 			// * The rest of the arguments will form a block that acts as the
 			//   body of the macro.
 			case "defmacro":
-				ret, err = DefMacro(rt, scope, list.Rest().(*List))
+				ret, err = DefMacro(rt, scope, list)
 				if err != nil {
 					return nil, err
 				}
@@ -511,7 +512,7 @@ tco:
 					return nil, MakeError(rt, list, "'let' needs at list 1 aruments")
 				}
 
-				letScope := MakeScope(scope.(*Scope))
+				letScope := MakeScope(rt, scope.(*Scope), nil)
 
 				// Since we're using IColl for the bindings, we can use either lists
 				// or vectors or even hashmaps for bindings
@@ -565,6 +566,7 @@ tco:
 			default:
 				// Evaluating all the elements of the list
 				listExprs, e := evalForm(rt, scope, list)
+
 				if e != nil {
 					return nil, e
 				}
@@ -589,8 +591,8 @@ tco:
 					if e != nil {
 						return nil, e
 					}
-
 					rt.Stack.Push(list, fn)
+
 					body := append(
 						fn.GetBody().ToSlice(),
 						// Add the PopStack instruction to clean up the stack after
@@ -607,6 +609,7 @@ tco:
 					fn := f.(*NativeFunction)
 
 					rt.Stack.Push(list, fn)
+
 					ret, err = fn.Apply(
 						rt,
 						scope,
diff --git a/bootstrap/pkg/core/function.go b/bootstrap/pkg/core/function.go
index 88d4d1f..c641399 100644
--- a/bootstrap/pkg/core/function.go
+++ b/bootstrap/pkg/core/function.go
@@ -157,7 +157,7 @@ func MakeFunction(n Node, scope IScope, params IColl, body *Block) *Function {
 // MakeFnScope a new scope for the body of a function. It binds the `bindings`
 // to the given `values`.
 func MakeFnScope(rt *Runtime, parent IScope, bindings IColl, values IColl) (*Scope, IError) {
-	scope := MakeScope(parent.(*Scope))
+	scope := MakeScope(rt, parent.(*Scope), nil)
 	// TODO: Implement destructuring
 	binds := bindings.ToSlice()
 	exprs := values.ToSlice()
@@ -169,6 +169,16 @@ func MakeFnScope(rt *Runtime, parent IScope, bindings IColl, values IColl) (*Sco
 		if lastBinding.GetType() == ast.Symbol && lastBinding.(*Symbol).IsRestable() {
 			numberOfBindings = len(binds) - 1
 		}
+
+		if lastBinding.GetType() == ast.Symbol && !lastBinding.(*Symbol).IsRestable() && numberOfBindings < len(exprs) {
+			return nil, MakeSemanticError(
+				rt,
+				values.(IExpr),
+				errors.E0002,
+				fmt.Sprintf("expected '%d' arguments, got '%d'.", bindings.Count(), values.Count()),
+			)
+
+		}
 	}
 
 	if numberOfBindings > len(exprs) {
@@ -201,7 +211,7 @@ func MakeFnScope(rt *Runtime, parent IScope, bindings IColl, values IColl) (*Sco
 			// next.
 			rest := MakeEmptyList(MakeNodeFromExpr(binds[i]))
 
-			if i == len(exprs)-1 {
+			if i <= len(exprs)-1 {
 				// If the number of values matches the number of bindings
 				// or it is more than that create a list from them
 				// to pass it to the last argument that has to be Restable (e.g &x)
@@ -260,6 +270,7 @@ func (f *NativeFunction) Apply(rt *Runtime, scope IScope, n Node, args *List) (I
 
 func MakeNativeFn(name string, f nativeFnHandler) NativeFunction {
 	return NativeFunction{
+		Node: MakeNodeFromLocation(ast.MakeUnknownLocation()),
 		name: name,
 		fn:   f,
 	}
diff --git a/bootstrap/pkg/core/macro.go b/bootstrap/pkg/core/macro.go
index e1f2d4e..59644aa 100644
--- a/bootstrap/pkg/core/macro.go
+++ b/bootstrap/pkg/core/macro.go
@@ -18,7 +18,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 package core
 
-import "serene-lang.org/bootstrap/pkg/ast"
+// TODO:
+// * Add support for `before` and `after` state in macroexpantion
+//   and call stack. So in case of an error. Users should be able
+//   to see the forms before and after expansion.
+
+import (
+	"serene-lang.org/bootstrap/pkg/ast"
+)
 
 // Serene macros are in fact functions with the `isMacro` flag set to true.
 // We have only normal macro implementation in bootstrap version of serene in
@@ -84,6 +91,7 @@ func macroexpand(rt *Runtime, scope IScope, form IExpr) (IExpr, IError) {
 	var macro *Function
 	var e IError
 	ok := false
+	//form := expr
 
 	for {
 		macro, ok = isMacroCall(rt, scope, form)
diff --git a/bootstrap/pkg/core/namespace.go b/bootstrap/pkg/core/namespace.go
index 349b6c0..75f5679 100644
--- a/bootstrap/pkg/core/namespace.go
+++ b/bootstrap/pkg/core/namespace.go
@@ -160,7 +160,7 @@ func requireNS(rt *Runtime, ns *Symbol) (*Namespace, IError) {
 		)
 	}
 
-	namespace := MakeNS(ns.GetName(), source)
+	namespace := MakeNS(rt, ns.GetName(), source)
 	namespace.setForms(body)
 
 	return &namespace, nil
@@ -252,8 +252,9 @@ func RequireNamespace(rt *Runtime, namespace IExpr) (IExpr, IError) {
 }
 
 // MakeNS creates a new namespace with the given `name` and `source`
-func MakeNS(name string, source string) Namespace {
-	s := MakeScope(nil)
+func MakeNS(rt *Runtime, name string, source string) Namespace {
+	s := MakeScope(rt, nil, &name)
+
 	return Namespace{
 		name:      name,
 		rootScope: *s,
diff --git a/bootstrap/pkg/core/numbers.go b/bootstrap/pkg/core/numbers.go
index 93c39fd..12b6d65 100644
--- a/bootstrap/pkg/core/numbers.go
+++ b/bootstrap/pkg/core/numbers.go
@@ -158,7 +158,7 @@ func (d Double) F64() float64 {
 	return d.value
 }
 
-func MakeNumberFromStr(strValue string, isDouble bool) (INumber, error) {
+func MakeNumberFromStr(n Node, strValue string, isDouble bool) (INumber, error) {
 	var ret INumber
 
 	if isDouble {
@@ -169,6 +169,7 @@ func MakeNumberFromStr(strValue string, isDouble bool) (INumber, error) {
 		}
 
 		ret = Double{
+			Node:  n,
 			value: v,
 		}
 	} else {
@@ -178,6 +179,7 @@ func MakeNumberFromStr(strValue string, isDouble bool) (INumber, error) {
 		}
 
 		ret = Integer{
+			Node:  n,
 			value: v,
 		}
 	}
diff --git a/bootstrap/pkg/core/parser.go b/bootstrap/pkg/core/parser.go
index 8fc50d3..ac1362a 100644
--- a/bootstrap/pkg/core/parser.go
+++ b/bootstrap/pkg/core/parser.go
@@ -341,8 +341,9 @@ func readNumber(parser IParsable, neg bool) (IExpr, IError) {
 			break
 		}
 	}
-
-	value, err := MakeNumberFromStr(result, isDouble)
+	n := MakeSinglePointNode(parser.GetSource(), parser.GetLocation())
+	n.location.DecStart(len(result))
+	value, err := MakeNumberFromStr(n, result, isDouble)
 
 	if err != nil {
 		return nil, makeErrorFromError(parser, err)
@@ -425,6 +426,7 @@ func readList(parser IParsable) (IExpr, IError) {
 
 	node.location.DecStart(1)
 	node.location.IncEnd(1)
+
 	return MakeList(*node, list), nil
 }
 
diff --git a/bootstrap/pkg/core/printer.go b/bootstrap/pkg/core/printer.go
index 8c0bb2f..ecadfb9 100644
--- a/bootstrap/pkg/core/printer.go
+++ b/bootstrap/pkg/core/printer.go
@@ -85,9 +85,10 @@ func printError(rt *Runtime, err IError, stage int) {
 	}
 
 	color.Yellow.Printf(
-		"%d: At '%s'\n",
+		"%d: At '%s':%d\n",
 		stage,
 		source.Path,
+		source.LineNumberFor(loc.GetStart()),
 	)
 
 	color.White.Printf("%s\n", lines)
@@ -115,11 +116,17 @@ func printErrorWithTraceBack(rt *Runtime, err IError) {
 
 		var lines string
 		for i := startline; i <= endline; i++ {
-			fLoc := t.Fn.GetLocation()
-			line := fLoc.GetSource().GetLine(i)
-			if line != "----" {
-				lines += fmt.Sprintf("%d:\t%s\n", i, line)
+			fLoc := t.Caller.GetLocation()
+
+			if fLoc.IsKnownLocaiton() {
+				line := fLoc.GetSource().GetLine(i)
+				if line != "----" {
+					lines += fmt.Sprintf("%d:\t%s\n", i, line)
+				}
+			} else {
+				lines += "Builtin\n"
 			}
+
 		}
 
 		color.Yellow.Printf(
@@ -137,6 +144,7 @@ func printErrorWithTraceBack(rt *Runtime, err IError) {
 }
 
 func PrintError(rt *Runtime, err IError) {
+
 	switch err.GetErrType() {
 	case SyntaxError, SemanticError:
 		printError(rt, err, 0)
diff --git a/bootstrap/pkg/core/runtime.go b/bootstrap/pkg/core/runtime.go
index bca2701..3b1370d 100644
--- a/bootstrap/pkg/core/runtime.go
+++ b/bootstrap/pkg/core/runtime.go
@@ -115,7 +115,7 @@ func (r *Runtime) GetNS(ns string) (*Namespace, bool) {
 // CreateNS is a helper function to create a namespace and set it to be
 // the current namespace of the runtime. `MakeNS` is much preferred
 func (r *Runtime) CreateNS(name string, source string, setAsCurrent bool) {
-	ns := MakeNS(name, source)
+	ns := MakeNS(r, name, source)
 
 	if setAsCurrent {
 		r.currentNS = name
diff --git a/bootstrap/pkg/core/scope.go b/bootstrap/pkg/core/scope.go
index 9b65527..63fd1a6 100644
--- a/bootstrap/pkg/core/scope.go
+++ b/bootstrap/pkg/core/scope.go
@@ -23,6 +23,8 @@ import "fmt"
 type IScope interface {
 	Lookup(rt *Runtime, k string) *Binding
 	Insert(k string, v IExpr, public bool)
+	GetNS(rt *Runtime) *Namespace
+	SetNS(ns *string)
 }
 
 type Binding struct {
@@ -33,6 +35,7 @@ type Binding struct {
 type Scope struct {
 	bindings map[string]Binding
 	parent   *Scope
+	ns       *string
 }
 
 func (s *Scope) Lookup(rt *Runtime, k string) *Binding {
@@ -42,6 +45,9 @@ func (s *Scope) Lookup(rt *Runtime, k string) *Binding {
 
 	v, ok := s.bindings[k]
 	if ok {
+		if rt.IsDebugMode() {
+			fmt.Printf("[DEBUG] Found '%s': '%s'\n", k, v.Value.String())
+		}
 		return &v
 	}
 
@@ -52,6 +58,10 @@ func (s *Scope) Lookup(rt *Runtime, k string) *Binding {
 	builtin := rt.LookupBuiltin(k)
 
 	if builtin != nil {
+		if rt.IsDebugMode() {
+			fmt.Printf("[DEBUG] Found builtin '%s': '%s'\n", k, builtin)
+		}
+
 		return &Binding{builtin, true}
 	}
 
@@ -62,9 +72,36 @@ func (s *Scope) Insert(k string, v IExpr, public bool) {
 	s.bindings[k] = Binding{Value: v, Public: public}
 }
 
-func MakeScope(parent *Scope) *Scope {
+func (s *Scope) GetNS(rt *Runtime) *Namespace {
+	if s.ns == nil {
+		panic("A scope with no namespace !!!!")
+	}
+	ns, ok := rt.GetNS(*s.ns)
+	if !ok {
+		panic(fmt.Sprintf("A scope with the wrong namespace! '%s'", s.ns))
+	}
+	return ns
+}
+
+func (s *Scope) SetNS(ns *string) {
+	s.ns = ns
+}
+
+func MakeScope(rt *Runtime, parent *Scope, namespace *string) *Scope {
+	var belongsTo *string
+
+	if parent != nil {
+		nsName := parent.GetNS(rt).GetName()
+		belongsTo = &nsName
+	} else if namespace == nil {
+		panic("When the 'parent' is nil, you have to provide the 'namespace' name.")
+	} else {
+		belongsTo = namespace
+	}
+
 	return &Scope{
 		parent:   parent,
 		bindings: map[string]Binding{},
+		ns:       belongsTo,
 	}
 }
diff --git a/bootstrap/pkg/core/sforms.go b/bootstrap/pkg/core/sforms.go
index aaa806f..695df6b 100644
--- a/bootstrap/pkg/core/sforms.go
+++ b/bootstrap/pkg/core/sforms.go
@@ -67,40 +67,40 @@ func DefMacro(rt *Runtime, scope IScope, args *List) (IExpr, IError) {
 
 	// TODO: Add support for docstrings and meta
 
-	switch args.Count() {
-	case 3:
-		name := args.First()
-
-		if name.GetType() != ast.Symbol {
-			return nil, MakeError(rt, name, "the first argument of 'defmacro' has to be a symbol")
-		}
-
-		sym := name.(*Symbol)
-
-		var params IColl
-		body := MakeEmptyBlock()
-
-		arguments := args.Rest().First()
-
-		// TODO: Add vector in here
-		// Or any other icoll
-		if arguments.GetType() == ast.List {
-			params = arguments.(IColl)
-		}
-
-		if args.Count() > 2 {
-			body.SetContent(args.Rest().Rest().(*List).ToSlice())
-		}
-
-		macro := MakeMacro(scope, sym.GetName(), params, body)
-
-		ns := rt.CurrentNS()
-		ns.DefineGlobal(sym.GetName(), macro, true)
-
-		return macro, nil
+	if args.Count() < 2 {
+		return nil, MakeError(rt, args, "'defmacro' form need at least 2 arguments")
 	}
 
-	return nil, MakeError(rt, args, "'defmacro' form need at least 2 arguments")
+	name := args.Rest().First()
+
+	if name.GetType() != ast.Symbol {
+		return nil, MakeError(rt, name, "the first argument of 'defmacro' has to be a symbol")
+	}
+
+	sym := name.(*Symbol)
+
+	var params IColl
+	body := MakeEmptyBlock()
+
+	arguments := args.Rest().Rest().First()
+
+	// TODO: Add vector in here
+	// Or any other icoll
+	if arguments.GetType() == ast.List {
+		params = arguments.(IColl)
+	}
+
+	if args.Count() > 2 {
+		body.SetContent(args.Rest().Rest().Rest().(*List).ToSlice())
+	}
+
+	macro := MakeMacro(scope, sym.GetName(), params, body)
+
+	ns := scope.GetNS(rt)
+	ns.DefineGlobal(sym.GetName(), macro, true)
+
+	return macro, nil
+
 }
 
 // Fn defines a function inside the given scope `scope` with the given `args`.
diff --git a/bootstrap/pkg/core/types.go b/bootstrap/pkg/core/types.go
index ebcbb99..8a199a1 100644
--- a/bootstrap/pkg/core/types.go
+++ b/bootstrap/pkg/core/types.go
@@ -74,6 +74,10 @@ type IExpr interface {
 	IScopable
 }
 
+// TODO: Add helper functions to reach methods on Node.location. For example
+// Node.location.DecStart() has to have a helper on the Node liek:
+// Node.DecStartLocation
+
 // Node struct is simply representing a Node in the AST which provides the
 // functionalities required to trace the code based on the location.
 type Node struct {