That way, if there is some hidden trapdoor out there, no one will be able to use it without us knowing about it.

Lastly, he described the events of the afternoon, the opening of the hidden trapdoor and the discovery of the workshops below.

In response to the signal, a hidden trapdoor pushed upward.

Susannah moved slowly across the cracked and dirty linoleum, looking for a hidden trapdoor.

The first change caused the program to insert a hidden trapdoor each time it compiled the Unix operating system.

Escott hadn't bothered to lift the hidden trapdoor under the kitchen table to see if I was in.

Hiro squats down, looking away from the scroll, and pulls up one of the hidden trapdoors that lead down into the tunnel system.

People can't find a trapdoor so they say, oh, deary me, what a hidden trapdoor it must be.

"I feel like I fell through a hidden trapdoor and into a giant Mixmaster," he said, hoping for a smile.

Without this careful search, he would never have discovered the existence of the hidden trapdoor.