" This is the outlet, " he thought, " the second outlet through which 'he' passes" .

“这是出口，”他想，“‘他’经过的第二个出口”。

The trap-door was open beside him; it meant possible safety, because there remained the second outlet.

他身边的活板门开着。这意味着可能的安全，因为还有第二个出口。