They are sufficient to frighten dangerous intruders.

Or that we closed it to keep dangerous intruders out.

The powerful, complicated wards Khelben had set upon the tower offered no hint of the dangerous intruder's presence.

He would have done so only if discovered by some dangerous intruder.

A dangerous intruder was aboard!

After an uneasy interval, his cabin intercom came to life and he heard Riker announce that dangerous intruders were loose on the ship.

Anyone would be worried in a house where a dangerous intruder had just been captured, even though the menace was over.

He regarded the newcomer as Lieutenant Harold had at first: as a possibly dangerous intruder.

Alia's eyes popped open and she stared at the ghola as though she'd been wakened by a dangerous intruder.

She contrasts them with films like Panic Room, in which the female protagonists instead defend against dangerous intruders.