diff --git a/rugnux/Rugnux.cpp b/rugnux/Rugnux.cpp
index 01587643d..d990985d7 100644
--- a/rugnux/Rugnux.cpp
+++ b/rugnux/Rugnux.cpp
@@ -1326,7 +1326,20 @@ ProcessResult Rugnux::RunAllPasses(RugnuxObserver *observer) {
         pass1.pass_number = 1;
         pass1.pass_count = 2;
         if (cancelled_) { config_.output_prefix = base_prefix; return pass1; }
-        if (gonio_snapshot) experiment_.Goniometer(*gonio_snapshot);   // undo the pre-pass goniometer shift
+        // Undo the pre-pass goniometer shift (a sub-range or strided run moves start/increment inside
+        // the pass), but KEEP an axis direction the pass changed. The rotation-axis sign rescue runs
+        // inside the pass and adopts the opposite axis when the file's own indexes almost nothing;
+        // restoring the snapshot wholesale threw that away, handing pass 2 the sign that failed and
+        // then applying pass 1's fitted rotation scale to the axis it was not fitted on. It
+        // self-healed - pass 2's rescue fires again and a wrong sign indexes almost no frames - but
+        // only by repeating a whole first pass, and only while "a wrong sign always scores below
+        // half" holds, which is an invariant nothing states or tests.
+        if (gonio_snapshot) {
+            GoniometerAxis restored = *gonio_snapshot;
+            if (const auto after_pass1 = experiment_.GetGoniometer())
+                restored.Axis(after_pass1->GetAxis());
+            experiment_.Goniometer(restored);
+        }
         // A measured spot budget is the pass's own, not the run's: give the second pass the same list to
         // measure from, so the two passes cannot ratchet each other down. The canonical pass then reads
         // the budget off the refined geometry, where the spots that do lie on the lattice actually do.
@@ -1475,8 +1488,15 @@ ProcessResult Rugnux::RunAllPasses(RugnuxObserver *observer) {
                 // only costs a pass on a crystal that was going to be wrong otherwise.
                 experiment_.BeamX_pxl(header_geometry[0]).BeamY_pxl(header_geometry[1])
                            .DetectorDistance_mm(header_geometry[2]);
-                if (prepass_rotation_scale_ && gonio_snapshot)
-                    experiment_.Goniometer(*gonio_snapshot);   // and the header rotation angles with it
+                if (prepass_rotation_scale_ && gonio_snapshot) {
+                    // The header rotation angles with it - but not the axis DIRECTION, which is not
+                    // part of the geometry being reverted and may have been corrected by the sign
+                    // rescue (see the restore before pass 2).
+                    GoniometerAxis restored = *gonio_snapshot;
+                    if (const auto current = experiment_.GetGoniometer())
+                        restored.Axis(current->GetAxis());
+                    experiment_.Goniometer(restored);
+                }
                 config_.output_prefix = base_prefix;
                 auto redo = RunPipeline(observer, /*write_output=*/true, /*geometry_prepass=*/false);
                 redo.post_refine = pass1.post_refine;