The window went clear, and Sarah saw what was producing the noise—a massive metal shape had blotted out the sky, and was rapidly descending on them. There was no alien architecture here, and the rumble she heard came not from any alien super technology but from conventional Impulse engines, knocking down some of the ramshackle slave-camp shelters and sending the enemy forces scattering. Cannons mounted along its underside fired into retreating ranks, turning them into distant smears of red mud.