10 o'clock
`` Understand , '' said the captain , `` you will be asked to land not only in the dark but behind the enemy lines , not knowing who or what is below . '' `` We understand , '' said Hal quietly . `` I have come to offer you this opportunity , '' said Captain O'Neill quietly . `` Tonight -- the exact time is 10 o'clock -- we attack in force . In comparison , the assaults before this have been as nothing . I say we , but I mean chiefly , of course , the French . There will be some American troops in the advance , however .