diff --git a/mcp/event.go b/mcp/event.go
index bbb3e6c8..2b02a078 100644
--- a/mcp/event.go
+++ b/mcp/event.go
@@ -337,12 +337,15 @@ func (s *MemoryEventStore) After(_ context.Context, sessionID, streamID string,
 		if !ok {
 			return nil, fmt.Errorf("MemoryEventStore.After: unknown stream ID %v in session %q", streamID, sessionID)
 		}
-		start := index + 1
-		if dl.first > start {
+		start := (index + 1) - dl.first
+		if start < 0 {
 			return nil, fmt.Errorf("MemoryEventStore.After: index %d, stream ID %v, session %q: %w",
 				index, streamID, sessionID, ErrEventsPurged)
 		}
-		return slices.Clone(dl.data[start-dl.first:]), nil
+		if start >= len(dl.data) {
+			return nil, nil
+		}
+		return slices.Clone(dl.data[start:]), nil
 	}
 
 	return func(yield func([]byte, error) bool) {
diff --git a/mcp/event_test.go b/mcp/event_test.go
index 91ddb9d7..fedc92c5 100644
--- a/mcp/event_test.go
+++ b/mcp/event_test.go
@@ -299,7 +299,11 @@ func TestMemoryEventStoreAfter(t *testing.T) {
 		{"S1", "1", 0, []string{"d2", "d3"}, ""},
 		{"S1", "1", 1, []string{"d3"}, ""},
 		{"S1", "1", 2, nil, ""},
+		{"S1", "1", 3, nil, ""},
+		{"S1", "1", 100, nil, ""}, // past the end of stream "1" (highest is 2)
 		{"S1", "2", 0, nil, ""},
+		{"S1", "2", 1, nil, ""},
+		{"S1", "2", 100, nil, ""},
 		{"S1", "3", 0, nil, "unknown stream ID"},
 		{"S2", "0", 0, nil, "unknown session ID"},
 	} {