The intruder must have been hidden inside some place.

闯入者肯定是藏在什么地方了
Show me where the brother slept.

带我去哥哥的房间
The boy sleeps there every night.

小男孩每晚都睡在这儿
Gazing at the only light source outside in the corridor.

盯着从走廊投进来的唯一光线
He'd recognise every shape, every outline,

他会认出每个人的形态和轮廓
the silhouette of everyone who came to the door.

每一个走到门前的人的剪影
OK, so?

那又如何
So if someone approaches the door who he doesn't recognise,

那样如果有一个他没见过的人走到门前
an intruder, maybe he can even see the outline of a weapon.

就知道是闯入者或许他都能看到武器的轮廓
What would he do?

他会怎么做
In the precious few seconds before they came into the room,

在他们闯进来之前珍贵的几秒钟内
how would he use them if not to cry out?

他如果没有大声呼救会怎么做