Swarm returned

[eleanor20]

I collected a swarm locally in may. The queen was marked and all was well. Due to a little accident I had with the QE during an inspection they ended up being brood and a half as the queen moved up and layed in the super. This was not a problem and still seemed to be going well until the weather got awful and I was unable to inspect fully for what seemed like forever. They caught me by surprise and swarmed on 5th July. I did a really thorough check, removed a few queen cells and left one nice looking one. Since I knew the queen was not in there I took the opportunity to put a queen excluder back in above the brood box.
My plan was then to leave for about 3weeks to allow hatching and mating.
So today we have some sunshine and they tried to swarm again! This time they started to cluster but then returned to the hive.

My guess is that I missed a queen cell (and I was so careful not to ) in the half part of the brood and a half, and the queen is now trapped above the QE.

So before I suit up and go out to have a look inside the hive I need a plan.
What do you think might be happening and what would you do with them?

 

[enrico]

Difficult to say before you know where the queen is. If she can't get out you may be running a hive with the ok'd queen and a virgin. What I would do is find the old queen and continue as per an AS. In other words old queen with one frame on old site where all flying bees will go, all other bees on new site. Check again for queen cells and remove all but one charged one. If there are none I would leave it alone as hopefully you have a virgin in there!
That's what I would do anyway!