diff --git a/smcpp/model.py b/smcpp/model.py
index 527fd2e..245c6a9 100644
--- a/smcpp/model.py
+++ b/smcpp/model.py
@@ -235,7 +235,16 @@ def for_pop(self, pid):
             return self.model1
         else:
             assert i == 1
-            return _concat_models(self.model1, self.model2, self.split, pid)
+            assert self.model1.N0 == self.model2.N0
+            assert self.model1._spline_class is self.model2._spline_class
+            k1, k2 = [np.searchsorted(m.knots, self.split) for m in (self.model1, self.model2)]
+            kts = np.r_[self.model2.knots[:k2], [self.split], self.model1.knots[k1 + 1:]]
+            m = SMCModel(kts, self.model1.N0, self.model2._spline_class, self.model2.pid)
+            m[:k2] = self.model2[:k2]
+            m[k2] = ad.admath.log(self.model1(self.split).item())
+            m[k2 + 1:] = self.model1[k1 + 1:]
+            return m
+            # return _concat_models(self.model1, self.model2, self.split)
 
     # Propagate changes from submodels up
     @targets('model update')
@@ -338,7 +347,7 @@ def __setitem__(self, coords, x):
         self._models[a][cc] = x
 
 
-def _concat_models(m1, m2, t, pid):
+def _concat_models(m1, m2, t):
     if m1.N0 != m2.N0:
         raise RuntimeException()
     cs1 = np.cumsum(m1.s)
diff --git a/smcpp/plotting.py b/smcpp/plotting.py
index dee1847..3910844 100644
--- a/smcpp/plotting.py
+++ b/smcpp/plotting.py
@@ -85,12 +85,6 @@ def g(x, y, label, data=data, **kwargs):
                     # if not logy:
                     #     y *= 1e-3
                     series.append([None, x2, y2, ax.scatter, off, m.N0, g])
-            if split:
-                for i in 1, 2:
-                    x = series[-i][1]
-                    coords = x <= mb.split
-                    for j in 1, 2:
-                        series[-i][j] = series[-i][j][coords]
         else:
             x = np.cumsum(d['s'])
             x = np.insert(x, 0, 0)[:-1]