sledged said:
To control all means of communication to prisioners. In this case, the imprisoned queen.
Hm. What would work great for that would be a item that shunts the sending over to someone else, to be answered in the Queen's voice.
Although, in this case, (issuing a Sending to the doppel-Queen while she's in sight) would require some real-time coordination between the doppelgangers and the captors - which, if it's truly a complex plot they're trying to pull off, they'd go for some sort of Permanant long-range Telepathic Bond, so the captor who has the sending "tap" can immediately ask the doppel-Queen where 'she' is, and reply in her voice.
Or, really, a pair of items that shunt any divination or other spell (sending is evocation) meant for the queen to the doppel-Queen would work, and eliminate the middle-man. A high-power Misdirection.
At that caster level, the party cleric would have True Seeing, so it's somewhat moot (assuming the queen's advisor trusts the cleric casting it on him).
And, if not, you could use Arcane Sight or the like to narrow down which item on the doppel-Queen would be providing that functionality. (Where'd that extra ring come from, Majesty? Care if I identify it? It's magic, if you didn't know, and we'd hate for something harmful to be on your person.)
Anywa. I'm rambling.
Koewn