Jack gave her a look that would have burned through a vault door.

"How many people know the combination of the vault door?"

And the vault door might well stand an atomic attack.

And even if he came around, the wall of ice behind him closed the pass like a vault door.

They would see and probably hear the vault door being opened.

He moved to the vault door, saying, 'They already have a head start.

When he got to the vault door, she called out.

The reason for its short depth was a vault door.

To help the cause along, he again started to approach the vault door.

As a matter of fact, the vault door was unlocked.