diff --git a/trade.py b/trade.py
index 9528d079..80c2aa19 100644
--- a/trade.py
+++ b/trade.py
@@ -50,7 +50,8 @@ def parse_command_line():
     parser.add_argument('--unique', help='Only visit each station once', default=False, required=False, action='store_true')
     parser.add_argument('--insurance', metavar="<Credits>", help="Reserve at least this many credits", type=int, default=0, required=False)
     parser.add_argument('--margin', metavar="<Error Margin>", help="Reduce gains by this much to provide a margin of error for market fluctuations (e.g. 0.25 reduces gains by 1/4). 0<=m<=0.25. Default: 0.02", default=0.02, type=float, required=False)
-    parser.add_argument('--debug', help="Enable verbose output", default=False, required=False, action='store_true')
+    parser.add_argument('--detail', help="Give detailed jump information for multi-jump hops", default=False, required=False, action='store_true')
+    parser.add_argument('--debug', help="Enable diagnostic output", default=False, required=False, action='store_true')
     parser.add_argument('--routes', metavar="<MaxRoutes>", help="Maximum number of routes to show", type=int, default=1, required=False)
 
     args = parser.parse_args()
@@ -133,11 +134,12 @@ def main():
     parse_command_line()
 
     startCr = args.credits - args.insurance
-    routes = [ Route([src], [], startCr, 0, 0) for src in origins ]
+    routes = [ Route(stations=[src], hops=[], jumps=[], startCr=startCr, gainCr=0) for src in origins ]
     numHops =  args.hops
     lastHop = numHops - 1
 
-    print("From %s via %s to %s with %d credits for %d hops" % (originName, viaName, destName, startCr, numHops))
+    if args.debug:
+        print("From %s via %s to %s with %d credits for %d hops" % (originName, viaName, destName, startCr, numHops))
 
     calc = TradeCalc(tdb, debug=args.debug, capacity=args.capacity, maxUnits=maxUnits, margin=args.margin, unique=args.unique)
     for hopNo in range(numHops):
@@ -163,7 +165,7 @@ def main():
 
     routes.sort()
     for i in range(0, min(len(routes), args.routes)):
-        print(routes[i])
+        print(routes[i].detail(args.detail))
 
 
 if __name__ == "__main__":
diff --git a/tradecalc.py b/tradecalc.py
index 21234612..a18326bb 100644
--- a/tradecalc.py
+++ b/tradecalc.py
@@ -20,32 +20,40 @@ def __init__(self, stations, hops, startCr, gainCr, jumps):
         self.jumps = jumps
 
     def plus(self, dst, hop, jumps):
-        rvalue = Route(self.route + [dst], self.hops + [hop], self.startCr, self.gainCr + hop[1], self.jumps + jumps)
+        rvalue = Route(self.route + [dst], self.hops + [hop], self.startCr, self.gainCr + hop[1], self.jumps + [jumps])
         return rvalue
 
     def __lt__(self, rhs):
         if rhs.gainCr < self.gainCr: # reversed
             return True
-        return rhs.gainCr == self.gainCr and rhs.jumps < self.jumps
+        return rhs.gainCr == self.gainCr and len(rhs.jumps) < len(self.jumps)
     def __eq__(self, rhs):
-        return self.gainCr == rhs.gainCr and self.jumps == rhs.jumps
+        return self.gainCr == rhs.gainCr and len(self.jumps) == len(rhs.jumps)
 
-    def __repr__(self):
+    def str(self):
+        return "%s -> %s" % (self.route[0], self.route[-1])
+
+    def detail(self, verbose=False):
         src = self.route[0]
         credits = self.startCr
         gainCr = 0
         route = self.route
 
-        str = "%s -> %s:\n" % (src, route[-1])
+        str = self.str() + ":\n"
         for i in range(len(route) - 1):
             hop = self.hops[i]
-            str += " @ %-20s Buy" % route[i]
+            str += " >-> " if i == 0 else " -+- "
+            str += "%-20s Buy" % route[i]
             for item in hop[0]:
                 str += " %d*%s," % (item[1], item[0])
             str += "\n"
+            if verbose and len(self.jumps[i]) > 2:
+                str += "   |   "
+                str += " -> ".join([ jump.str() for jump in self.jumps[i] ])
+                str += "\n"
             gainCr += hop[1]
 
-        str += " $ %s %dcr + %dcr => %dcr total" % (route[-1], credits, gainCr, credits + gainCr)
+        str += " <-< %s %dcr + %dcr => %dcr total" % (route[-1], credits, gainCr, credits + gainCr)
 
         return str
 
@@ -109,9 +117,9 @@ def getBestHopFrom(self, src, credits, capacity=None, maxJumps=None, maxLy=None,
         if isinstance(src, str):
             src = self.tdb.getStation(src)
         hop = None
-        for (destSys, destStn, jumps, ly) in src.getDestinations(maxJumps=maxJumps, maxLy=maxLy, maxLyPer=maxLyPer):
+        for (destSys, destStn, jumps, ly, via) in src.getDestinations(maxJumps=maxJumps, maxLy=maxLy, maxLyPer=maxLyPer):
             load = self.getBestTrade(src, destStn, credits, capacity=capacity)
-            if load and (not hop or (load[1] > hop.gainCr or (load[1] == hop.gainCr and jumps < hop.jumps))):
+            if load and (not hop or (load[1] > hop.gainCr or (load[1] == hop.gainCr and len(jumps) < hop.jumps))):
                 hop = TradeHop(destSys=destSys, destStn=destStn, load=load[0], gainCr=load[1], jumps=jumps, ly=ly)
         return hop
 
@@ -128,29 +136,40 @@ def getBestHops(self, routes, credits, restrictTo=None, maxJumps=None, maxLy=Non
         perJumpLimit = maxJumpsPer if (maxJumpsPer or 0) > 0 else 0
         for route in routes:
             src = route.route[-1]
+            if self.debug: print("# route = %s" % route.str())
             startCr = credits + int(route.gainCr * safetyMargin)
-            routeJumps = route.jumps
+            routeJumps = len(route.jumps)
             jumpLimit = perJumpLimit
             if (maxJumps or 0) > 0:
                 jumpLimit = min(maxJumps - routeJumps, perJumpLimit) if perJumpLimit > 0 else maxJumps - routeJumps
-                if jumpLimit == 0:
+                if jumpLimit <= 0:
+                    if self.debug: print("Jump Limit")
                     continue
+            
             for (destSys, destStn, jumps, ly) in src.getDestinations(maxJumps=jumpLimit, maxLy=maxLy, maxLyPer=maxLyPer):
+                if self.debug:
+                    print("#destSys = %s, destStn = %s, jumps = %s, ly = %s" % (destSys.str(), destStn, "->".join([jump.str() for jump in jumps]), ly))
                 if not destStn in src.stations:
+                    if self.debug: print("#%s is not in my station list" % destStn)
                     continue
                 if restrictTo and destStn != restrictTo:
+                    if self.debug: print("#%s doesn't match restrict %s" % (destStn, restrictTo))
                     continue
                 if unique and destStn in route.route:
+                    if self.debug: print("#%s is already in the list, not unique" % destStn)
                     continue
                 trade = self.getBestTrade(src, destStn, startCr)
                 if not trade:
+                    if self.debug: print("#* No trade")
                     continue
                 dstID = destStn.ID
                 try:
                     best = bestToDest[dstID]
-                    if best[1].gainCr + best[2][1] >= route.gainCr + trade[1]:
+                    oldRouteGainCr = best[1].gainCr + best[2][1]
+                    newRouteGainCr = route.gainCr + trade[1]
+                    if oldRouteGainCr >= newRouteGainCr:
                         continue
-                except: pass
+                except KeyError: pass
                 bestToDest[dstID] = [ destStn, route, trade, jumps, ly ]
 
         result = []
diff --git a/tradedb.py b/tradedb.py
index 7543d24b..9a1753cc 100644
--- a/tradedb.py
+++ b/tradedb.py
@@ -91,17 +91,19 @@ def organizeTrades(self):
 
     def getDestinations(self, maxJumps=None, maxLy=None, maxLyPer=None):
         openList, closedList, destStations = Queue(), dict(), []
-        openList.put([self.system, 0, 0])
+        openList.put([self.system, [], 0])
         maxJumpDist = maxLyPer or sys.maxint
         while not openList.empty():
             (sys, jumps, dist) = openList.get()
-            if (maxJumps and jumps > maxJumps) or (maxLy and dist > maxLy):
+            if maxJumps and len(jumps) > maxJumps:
+                continue
+            if maxLy and dist > maxLy:
                 continue
             for stn in sys.stations:
                 if stn != self:
-                    destStations.append([sys, stn, jumps, dist])
-            jumps += 1
-            if (maxJumps and jumps > maxJumps):
+                    destStations.append([sys, stn, list(jumps), dist])
+            jumps.append(sys)
+            if (maxJumps and len(jumps) > maxJumps):
                 continue
             for (destSys, destDist) in sys.links.items():
                 if dist > maxLyPer:
@@ -110,7 +112,7 @@ def getDestinations(self, maxJumps=None, maxLy=None, maxLyPer=None):
                     continue
                 if destSys in closedList:
                     continue
-                openList.put([destSys, jumps, dist + destDist])
+                openList.put([destSys, list(jumps), dist + destDist])
                 closedList[destSys] = 1
         return destStations
 
@@ -120,8 +122,9 @@ def __repr__(self):
 
 
 class TradeDB(object):
-    def __init__(self, path=r'.\TradeDangerous.accdb'):
+    def __init__(self, path=r'.\TradeDangerous.accdb', debug=0):
         self.path = "Driver={Microsoft Access Driver (*.mdb, *.accdb)};DBQ=" + path
+        self.debug = debug
         self.load()
 
     def load(self, avoiding=[], ignoreLinks=False):
@@ -131,6 +134,8 @@ def load(self, avoiding=[], ignoreLinks=False):
 
         cur.execute('SELECT system FROM Stations GROUP BY system')
         self.systems = { row[0]: System(row[0]) for row in cur }
+        if self.debug:
+            print(self.systems)
         cur.execute("""SELECT frmSys.system, toSys.system, Links.distLy
                      FROM Stations AS frmSys, Links, Stations as toSys
                      WHERE frmSys.ID = Links.from AND toSys.ID = Links.to""")
@@ -148,7 +153,7 @@ def load(self, avoiding=[], ignoreLinks=False):
         """ Populate 'items' from the database """
         cur.execute('SELECT id, item FROM Items')
         self.items = { row[0]: row[1] for row in cur }
-        self.itemIDs = { self.items[name]: name for name in self.items }
+        self.itemIDs = { name: itemID for (itemID, name) in self.items.items() }
 
         stations, items = self.stations, self.items
 
@@ -157,7 +162,7 @@ def load(self, avoiding=[], ignoreLinks=False):
                     ' FROM Prices AS src INNER JOIN Prices AS dst ON src.item_id = dst.item_id'
                     ' WHERE src.buy_cr > 0 AND dst.sell_cr > src.buy_cr'
                     ' AND src.ui_order > 0 AND dst.ui_order > 0'
-                    ' ORDER BY (dst.sell_cr - src.buy_cr) DESC')
+                    )
         for row in cur:
             if not (items[row[2]] in avoiding):
                 stations[row[0]].addTrade(stations[row[1]], items[row[2]], row[2], row[3], row[4])
@@ -165,6 +170,32 @@ def load(self, avoiding=[], ignoreLinks=False):
         for station in stations.values():
             station.organizeTrades()
 
+        if self.debug:
+            self.validate()
+
+    def validate(self):
+        # Check that things correctly reference themselves.
+        for (stnID, stn) in self.stations.items():
+            if self.stations[stn.ID] != stn:
+                raise ValueError("Station not pointing to self correctly" % stn.station)
+        for (stnName, stnID) in self.stationIDs.items():
+            if self.stations[stnID].station.upper() != stnName:
+                raise ValueError("Station name not pointing to self correctly" % stnName)
+        for (itemID, item) in self.items.items():
+            if self.itemIDs[item] != itemID:
+                raise ValueError("Item %s not pointing to itself correctly" % item, itemID, item, self.itemIDs[item])
+        # Check that system links are bi-directional
+        for (name, sys) in self.systems.items():
+            if not sys.links:
+                raise ValueError("System %s has no links" % name)
+            if sys in sys.links:
+                raise ValueError("System %s has a link to itself!" % name)
+            if name in sys.links:
+                raise ValueError("System %s's name occurs in sys.links" % name)
+            for link in sys.links:
+                if not sys in link.links:
+                    raise ValueError("System %s does not have a reciprocal link in %s's links" % (name, link.str()))
+
     def getStation(self, name):
         if isinstance(name, Station):
             return name