The service passage was a vertical labyrinth of rusted pipework and narrow, crumbling concrete steps—a forgotten artery of the villa, choked with dust and stale, metallic air. The noise of the war was immense now, not just the far-off roar of the siege, but the sharp, echoing cracks of automatic fire and the terrible, wet sounds of close-quarters combat tearing through the air vents from the sub-levels below.

Marco secured the flimsy, hinged door behind us and turned, his face a grim, ...