"They're dead!" Sister Sandrine stammered into the telephone in her Saint-Sulpice residence. She was leaving a message on an answering machine. "Please pick up! They're all dead!" The first three phone numbers on the list had produced terrifying results -- a hysterical widow, a detective working late at a murder scene, and a somber priest consoling a bereaved family. All three contacts were dead. And now, as she called the fourth and final number -- the number she was not supposed to call unless the first three could not be reached -- she got an answering machine.

The outgoing message offered no name but simply asked the caller to leave a message.

"The floor panel has been broken!" she pleaded as she left the message. "The other three are dead!"

If that floor panel is ever broken, the faceless messenger had told her, it means the upper echelon has been breached. One of us has been mortally threatened and been forced to tell a desperate lie.

Sister Sandrine did not know the identities of the four men she protected, but the private phone numbers stashed beneath her bed were for use on only one condition.

All four are dead.

Call the numbers. Warn the others. Do not fail us in this.

A sudden explosion of rage erupted behind the monk's eyes. He lunged, lashing out with the candle stand like a club. As Sister Sandrine fell, her last feeling was an overwhelming sense of foreboding.

"Jesus had but one true message," Sister Sandrine said defiantly. "I cannot see that message in Opus Dei."

"I don't know!" Sister Sandrine said truthfully. "That secret is guarded by others." Others who are dead!

"Hang up the phone," a deep voice said from the doorway.

The precious truth is lost forever.

It was a silent alarm. Foolproof in its simplicity. The plan had amazed her when she first heard it. If the identity of one brother was compromised, he could tell a lie that would start in motion a mechanism to warn the others. Tonight, however, it seemed that more than one had been compromised.

Shaking, she set the phone back in the cradle.

The man advanced, his white fists gripping the iron stand. "You are a sister of the Church, and yet you serve them?"

Turning in terror, she saw the massive monk. He was clutching the heavy iron candle stand.

"They are dead," the monk said. "All four of them. And they have played me for a fool. Tell me where the keystone is."

"Please answer," she whispered in fear. "Where are you?"