While she stood on her precarious eminence, wildly gesticulating in her insane triumph, there was the report of a musket from down the street. She swayed for a brief moment upon the crumbling wall, uttered one heart-rending shriek of "Juanino!" and fell lifeless upon the ruins below. The interruption was but momentary. At the instant when the hapless Doña Mercedes fell, Jorge Arcos, desperately wounded, struggled from the ruins of Vallejo, followed by half a dozen of his men, all showing terrible signs of the struggle they had made to hold the position. While a portion of Jack’s force continued their gallant attempt to repel the French from the barricade, the rest swarmed into the house, only to be driven out again with heavy loss by the enemy, who, backed by a large force in the ruins, had now an overwhelming superiority in numbers. In the street the gigantic Pole, swept away from before Jack, returned to the attack at the head of a compact band of his compatriots, and the Spaniards, still fighting furiously, were driven back inch by inch through the gap in the barricade, their retirement being hastened by shots from the walls of the Casa Tobar, which, together with its neighbour, the ruined Casa Vega, had fallen into French hands. Save for the Casa Alvarez and the surrounding streets, the whole of the quarter towards Santa Engracia had now been captured, and Jack, extricating himself from the mêlée, saw that it was time to play his last card. "Señor," said Antonio, running up at this moment, "Don Cristobal sends me to say that he still holds his barricade, but that he will not be able to do so for more than a few minutes longer." "You are the man I want, Antonio," replied Jack. "Run to the Casa Alvarez, send every man of the reserve to me, and go into the cellars and fire the last of our mines. Don’t wait; do it at once."