Kirk's on his own with them, with Martel unable to afford to split his attention; he's aware enough of his surroundings to make sure his movements around the hive itself keep him out of easy reach, but his mind is necessarily elsewhere, following the smooth and practised motions of his hands, dipping into his well of power and feeling it moving through him, out into the world, changing and shifting-

The moment he releases the spell, nobody in the vicinity needs to be sensitive to realize. The change comes suddenly but in segments, bringing the hive down from beneath as the supports of the structure begin consecutively turning into sand, rushing out-

Martel, in the midst of this, is doing his best to bolt through the rushing sand before the whole damn thing comes down his head, but it's fast and forceful and he's stumbling, sweating with the exertion that was the spell itself in the first place.