Wellington's army continued its advance besieging Burgos in September, with the 68th at Olmos covering the siege and constructing breastworks in the valley at Monasterio de Rodilla in mid October. The French now showed signs of attacking, and attempting to out-flank the British forces around Madrid, and Wellington began another retreat back to Portugal in the rain and mud of autumn. The regiment went into winter quarters at Paços de Baixo and Paços de Cima in December. Due to its weakened state, 235 men fit for duty and 247 sick, it was briefly threatened with being combined with another weak regiment into a 'Provisional Battalion'. However the regiment shared in the recovery of Wellington's army as a whole and by April 1813 had 439 men fit with only 97 sick.