The goo says nothing now; it just bubbles, a pale riveting pool of hot spring mud.
The Master’s mind springs to a thought of his escape route, installed behind the console of the hidden comm room.
Rassilon can fly a shuttle, he reasons, clutching and releasing his hoodie like a worry doll. It stands to reason he found the button for the first part of the flight plan in the… and if he did, he must be on the return trip by now… as planned. The Doctor must have planned it; the bastard plans everything else. Kind of. Possibly. Maybe-probably. Idiot. Hopefully.
The Master then turns to Rose/Rosette and says, “You know what I want. Send it.” Then his fingers stab out weakly and he says, “Engage.”
But his eyes say, “…don’t tell him I’m a trekkie or I’ll turn you into kuchen dough, Little Miss Yellow Annoying.”
Once more a milky effigy, Rose/Rosette giggles as she sends the message through the point between Gallifrey’s two suns, the signal piggybacking on the TARDIS and riding on the tiny violin’s undetectable temporal contrail, hidden just enough, timed just so with three seconds to spare. It will make it through the mine cloud’s blind spot without detonating everytime, everywhere.
It must. The shuttle must be reached.
And Rassilon must hear.