diff --git a/graph/iterator/and_iterator.go b/graph/iterator/and_iterator.go
index f7da02f..2cf8691 100644
--- a/graph/iterator/and_iterator.go
+++ b/graph/iterator/and_iterator.go
@@ -190,8 +190,13 @@ func (it *And) checkContainsList(val graph.Value, lastResult graph.Value) bool {
 	for i, c := range it.checkList {
 		ok = c.Contains(val)
 		if !ok {
+			if err := c.Err(); err != nil {
+				it.err = err
+				return false
+			}
 			if lastResult != nil {
 				for j := 0; j < i; j++ {
+					// TODO(andrew-d): Should this result actually be used?
 					it.checkList[j].Contains(lastResult)
 				}
 			}
@@ -249,10 +254,18 @@ func (it *And) NextPath() bool {
 	if it.primaryIt.NextPath() {
 		return true
 	}
+	if err := it.primaryIt.Err(); err != nil {
+		it.err = err
+		return false
+	}
 	for _, sub := range it.internalIterators {
 		if sub.NextPath() {
 			return true
 		}
+		if err := sub.Err(); err != nil {
+			it.err = err
+			return false
+		}
 	}
 	return false
 }
diff --git a/graph/iterator/hasa_iterator.go b/graph/iterator/hasa_iterator.go
index 037772b..8647dbd 100644
--- a/graph/iterator/hasa_iterator.go
+++ b/graph/iterator/hasa_iterator.go
@@ -193,11 +193,16 @@ func (it *HasA) NextPath() bool {
 	if it.primaryIt.NextPath() {
 		return true
 	}
-	result := it.NextContains()
-	glog.V(4).Infoln("HASA", it.UID(), "NextPath Returns", result, "")
+	if err := it.primaryIt.Err(); err != nil {
+		it.err = err
+		return false
+	}
+
+	result := it.NextContains() // Sets it.err if there's an error
 	if it.err != nil {
 		return false
 	}
+	glog.V(4).Infoln("HASA", it.UID(), "NextPath Returns", result, "")
 	return result
 }
 
diff --git a/graph/iterator/linksto_iterator.go b/graph/iterator/linksto_iterator.go
index 16affac..0eebe78 100644
--- a/graph/iterator/linksto_iterator.go
+++ b/graph/iterator/linksto_iterator.go
@@ -126,6 +126,9 @@ func (it *LinksTo) Contains(val graph.Value) bool {
 		it.result = val
 		return graph.ContainsLogOut(it, val, true)
 	}
+	if err := it.primaryIt.Err(); err != nil {
+		it.err = err
+	}
 	return graph.ContainsLogOut(it, val, false)
 }
 
@@ -213,7 +216,11 @@ func (it *LinksTo) Close() error {
 
 // We won't ever have a new result, but our subiterators might.
 func (it *LinksTo) NextPath() bool {
-	return it.primaryIt.NextPath()
+	ret := it.primaryIt.NextPath()
+	if !ret {
+		it.err = it.primaryIt.Err()
+	}
+	return ret
 }
 
 // Register the LinksTo.
diff --git a/graph/iterator/materialize_iterator.go b/graph/iterator/materialize_iterator.go
index cff1c88..e38ac58 100644
--- a/graph/iterator/materialize_iterator.go
+++ b/graph/iterator/materialize_iterator.go
@@ -230,6 +230,9 @@ func (it *Materialize) Contains(v graph.Value) bool {
 	if !it.hasRun {
 		it.materializeSet()
 	}
+	if it.err != nil {
+		return false
+	}
 	if it.aborted {
 		return it.subIt.Contains(v)
 	}
@@ -249,6 +252,9 @@ func (it *Materialize) NextPath() bool {
 	if !it.hasRun {
 		it.materializeSet()
 	}
+	if it.err != nil {
+		return false
+	}
 	if it.aborted {
 		return it.subIt.NextPath()
 	}
diff --git a/graph/iterator/not_iterator.go b/graph/iterator/not_iterator.go
index 2617a98..a54b4bb 100644
--- a/graph/iterator/not_iterator.go
+++ b/graph/iterator/not_iterator.go
@@ -113,6 +113,13 @@ func (it *Not) Contains(val graph.Value) bool {
 		return graph.ContainsLogOut(it, val, false)
 	}
 
+	if err := it.primaryIt.Err(); err != nil {
+		it.err = err
+
+		// Explicitly return 'false', since an error occurred.
+		return false
+	}
+
 	it.result = val
 	return graph.ContainsLogOut(it, val, true)
 }
diff --git a/graph/iterator/optional_iterator.go b/graph/iterator/optional_iterator.go
index 84e7154..d645dc7 100644
--- a/graph/iterator/optional_iterator.go
+++ b/graph/iterator/optional_iterator.go
@@ -38,6 +38,7 @@ type Optional struct {
 	subIt     graph.Iterator
 	lastCheck bool
 	result    graph.Value
+	err       error
 }
 
 // Creates a new optional iterator.
@@ -77,7 +78,7 @@ func (it *Optional) ResultTree() *graph.ResultTree {
 }
 
 func (it *Optional) Err() error {
-	return it.subIt.Err()
+	return it.err
 }
 
 func (it *Optional) Result() graph.Value {
@@ -89,7 +90,11 @@ func (it *Optional) Result() graph.Value {
 // optional subbranch.
 func (it *Optional) NextPath() bool {
 	if it.lastCheck {
-		return it.subIt.NextPath()
+		ret := it.subIt.NextPath()
+		if !ret {
+			it.err = it.subIt.Err()
+		}
+		return ret
 	}
 	return false
 }
@@ -105,6 +110,7 @@ func (it *Optional) SubIterators() []graph.Iterator {
 func (it *Optional) Contains(val graph.Value) bool {
 	checked := it.subIt.Contains(val)
 	it.lastCheck = checked
+	it.err = it.subIt.Err()
 	it.result = val
 	return true
 }
diff --git a/graph/iterator/or_iterator.go b/graph/iterator/or_iterator.go
index e5b4e09..024ce74 100644
--- a/graph/iterator/or_iterator.go
+++ b/graph/iterator/or_iterator.go
@@ -174,7 +174,7 @@ func (it *Or) Result() graph.Value {
 }
 
 // Checks a value against the iterators, in order.
-func (it *Or) subItsContain(val graph.Value) bool {
+func (it *Or) subItsContain(val graph.Value) (bool, error) {
 	var subIsGood = false
 	for i, sub := range it.internalIterators {
 		subIsGood = sub.Contains(val)
@@ -182,15 +182,21 @@ func (it *Or) subItsContain(val graph.Value) bool {
 			it.currentIterator = i
 			break
 		}
+		if err := sub.Err(); err != nil {
+			return false, err
+		}
 	}
-	return subIsGood
+	return subIsGood, nil
 }
 
 // Check a value against the entire graph.iterator, in order.
 func (it *Or) Contains(val graph.Value) bool {
 	graph.ContainsLogIn(it, val)
-	anyGood := it.subItsContain(val)
-	if !anyGood {
+	anyGood, err := it.subItsContain(val)
+	if err != nil {
+		it.err = err
+		return false
+	} else if !anyGood {
 		return graph.ContainsLogOut(it, val, false)
 	}
 	it.result = val
@@ -231,7 +237,12 @@ func (it *Or) Size() (int64, bool) {
 // shortcircuiting, only allow new results from the currently checked graph.iterator
 func (it *Or) NextPath() bool {
 	if it.currentIterator != -1 {
-		return it.internalIterators[it.currentIterator].NextPath()
+		currIt := it.internalIterators[it.currentIterator]
+		ret := currIt.NextPath()
+		if !ret {
+			it.err = currIt.Err()
+		}
+		return ret
 	}
 	return false
 }
diff --git a/graph/iterator/value_comparison_iterator.go b/graph/iterator/value_comparison_iterator.go
index bffd640..84d949d 100644
--- a/graph/iterator/value_comparison_iterator.go
+++ b/graph/iterator/value_comparison_iterator.go
@@ -155,6 +155,7 @@ func (it *Comparison) NextPath() bool {
 	for {
 		hasNext := it.subIt.NextPath()
 		if !hasNext {
+			it.err = it.subIt.Err()
 			return false
 		}
 		if it.doComparison(it.subIt.Result()) {
@@ -174,7 +175,11 @@ func (it *Comparison) Contains(val graph.Value) bool {
 	if !it.doComparison(val) {
 		return false
 	}
-	return it.subIt.Contains(val)
+	ret := it.subIt.Contains(val)
+	if !ret {
+		it.err = it.subIt.Err()
+	}
+	return ret
 }
 
 // If we failed the check, then the subiterator should not contribute to the result