Again he thrust Jisbella before him and they ran, gasping and stumbling, through the blackness, down into the deepest reaches of South Quadrant. Jisbella fell twice, blundering against turns in the passages. Foyle took the lead and ran, holding the twenty-pound sledge in his hand, the handle extended before, him as an antenna. Then they crashed into a blank wall and realized they had reached the dead end of the corridor. They were boxed, trapped.