diff --git a/Facade.h b/Facade.h
index ee89ab1..442e767 100644
--- a/Facade.h
+++ b/Facade.h
@@ -25,16 +25,19 @@ struct Facade {
       const int64_t v[] = {version, version};
       facade->versioned.firstGeq(key, v, versionedIter, 2);
 
-      const uint8_t zero[] = {0};
+      static const uint8_t zero_[] = {0};
+      static const String zero{zero_, 1};
+
       if (reverse) {
         weaselab::VersionedMap::Iterator iter = versionedIter[1];
         weaselab::VersionedMap::Iterator endIter = versionedIter[0];
         String readUntil = end;
         for (; iter != endIter; --iter) {
           auto m = *iter;
-          auto mEnd = m.type == weaselab::VersionedMap::Set
-                          ? String(m.param1, m.param1Len) + String(zero, 1)
-                          : String(m.param2, m.param2Len);
+          const auto mEnd =
+              m.type == weaselab::VersionedMap::Set || m.param2Len == 0
+                  ? String(m.param1, m.param1Len) + zero
+                  : String(m.param2, m.param2Len);
           auto remaining =
               facade->unversionedRead(mEnd, readUntil, limit, true);
           result.insert(result.end(), remaining.begin(), remaining.end());
@@ -65,22 +68,21 @@ struct Facade {
         String readThrough = begin;
         for (; iter != endIter; ++iter) {
           auto m = *iter;
-          auto remaining = facade->unversionedRead(
-              readThrough, String(m.param1, m.param1Len), limit, false);
+          const auto mBegin = String(m.param1, m.param1Len);
+          auto remaining =
+              facade->unversionedRead(readThrough, mBegin, limit, false);
           result.insert(result.end(), remaining.begin(), remaining.end());
           if (limit == 0) {
             return result;
           }
           switch (m.type) {
           case weaselab::VersionedMap::Set: {
-            result.push_back(
-                {String(m.param1, m.param1Len), String(m.param2, m.param2Len)});
+            result.push_back({mBegin, String(m.param2, m.param2Len)});
             --limit;
             if (limit == 0) {
               return result;
             }
-            uint8_t zero[] = {0};
-            readThrough = String(m.param1, m.param1Len) + String(zero, 1);
+            readThrough = mBegin + zero;
           } break;
           case weaselab::VersionedMap::Clear:
             readThrough = String(m.param2, m.param2Len);
@@ -140,15 +142,26 @@ struct Facade {
                                                          const String &end,
                                                          int &limit,
                                                          bool reverse) const {
+    if (begin >= end) {
+      return {};
+    }
     std::vector<std::pair<String, String>> result;
     if (reverse) {
       if (unversioned.empty()) {
         return result;
       }
-      for (auto iter = --unversioned.lower_bound(end);
-           iter->first >= begin && limit > 0; --iter) {
+      auto iter = unversioned.lower_bound(end);
+      const auto beginIter = unversioned.begin();
+      if (iter == beginIter) {
+        return result;
+      }
+      --iter;
+      for (; iter->first >= begin && limit > 0; --iter) {
         result.push_back(*iter);
         --limit;
+        if (iter == beginIter) {
+          return result;
+        }
       }
     } else {
       for (auto iter = unversioned.lower_bound(begin),