Song Ning had a pretty good sense of balance and made it across the horizontal iron bridge without mishap.
She swiftly followed the two men through the doorway where they had disappeared.
Another passage lay beyond it.
Fortunately, she was just in time to see their light disappear to the left.
She hurried after them.
To the left was a long corridor with rooms on both sides, all their doors closed. Dim lights glowed at intervals overhead.
Song Ning dared not follow too closely.
She waited until the two men had paused in front of a door and gone through it before following again.
But when she reached the door, she found she could go no farther.
It was an iron-barred door with a numeric keypad.
A combination lock, of all things.
As Song Ning fretted, snatches of conversation drifted out from inside.
"...Can't even show up on time for the shift change. I'm fucking exhausted!"
"...You'd better watch yourself, kid. Don't get caught slipping..."
"...Stay sharp! Those people are stubborn as hell..."
Then she heard someone coming toward her.
Song Ning quickly slipped to the other side of the corridor and pressed herself against the wall, hiding in the darkness between two ceiling lights.
Fortunately, the corridor was dimly lit, and the lights were spaced far enough apart.
That gave her somewhere to hide.
The keypad beeped six times, and the iron door opened with a click.
Two more men in black emerged, also carrying a lantern.
Song Ning knew they weren't the same two men from before.
These were the two who had just finished their shift.
She was hiding on the other side of the iron door.
Neither man looked her way. Yawning, they shuffled off in the direction she had come from.
The lit area across