I went through Hive 1 this afternoon, to break down any queen cells in the top box (I found three) and check the bottom box with the new queen was OK. It wasn't. It had queen cells and no eggs or uncapped larvae. I can only suppose that the queen flew up when I opened the hive last week, as young queens occasionally do, and got lost. I don't want her misbegotten daughters, so I broke down all the cells, and gave them a frame from Hive 4 with lots of eggs in it. If they really are queenless, they'll raise a new one from that.