oom？ A woman was moving through the darkness； walking briskly toward the far left wall。 In front of her； a purplish beam of light swung back and forth across the floor； as if she were searching for something with a colored flashlight。
〃Qui est là？〃 Grouard demanded； feeling his adrenaline spike for a second time in the last thirty seconds。 He suddenly didn't know where to aim his gun or what direction to move。
〃PTS；〃 the woman replied calmly； still scanning the floor with her light。
Police Technique et Scientifique。 Grouard was sweating now。 I thought all the agents were gone！ He now recognized the purple light as ultraviolet； consistent with a PTS team； and yet he could not understand why DCPJ would be looking for evidence in here。
〃Votre nom！〃 Grouard yelled； instinct telling him something was amiss。 〃Répondez！〃
〃C'est mot；〃 the voice responded in calm French。 〃Sophie Neveu。〃
Somewhere in the distant recesses of Grouard's mind； the name registered。 Sophie Neveu？ That was the name of Saunière's granddaughter； wasn't it？ She used to e in here as a little kid； but that was years ago。 This couldn't possibly be her！ And even if it were Sophie Neveu； that was hardly a reason to trust her； Grouard had heard the rumors of the painful falling…out between Saunière and his granddaughter。
〃You know me；〃 the woman called。 〃And Robert Langdon did not kill my grandfather。 Believe me。〃
Warden Grouard was not about to take that on faith。 I need backup！ Trying his walkie…talkie again； he got only static。 The entrance was still a good twenty yards behind him； and Grouard began backing up slowly； choosing to leave his gun trained on the man on the floor。 As Grouard inched backward； he could see the woman across the room raising her UV light and scrutinizing a large painting that hung on the far side of the Salle des Etats； directly opposite the Mona Lisa。
Grouard gasped； realizing which painting it was。
What in the name of God is she doing？
Across the room； Sophie Neveu felt a cold sweat breaking across her forehead。 Langdon was still spread…eagle on the floor。 Hold on； Robert。 Almost there。 Knowing the guard would never actually shoot either of them； Sophie now turned her attention back to the matter at hand； scanning the entire area around one masterpiece in particular—another Da Vinci。 But the UV light revealed nothing out of the ordinary。 Not on the floor； on the walls； or even on the canvas itself。
There must be something here！
Sophie felt totally certain she had deciphered her grandfather's intentions correctly。
What else could he possibly intend？
The masterpiece she was examining was a five…foot…tall canvas。 The bizarre scene Da Vinci had painted included an awkwardly posed Virgin Mary sitting with Baby Jesus； John the Baptist； and the Angel Uriel on a perilous outcropping of rocks。 When Sophie was a little girl； no trip to the Mona Lisa had been plete without her grandfather dragging her across the room to see this second painting。
Grand…père； I'm here！ But I don't see it！
Behind her； Sophie could hear the guard trying to radio again for help。
Think！
She pictured the message scrawled on the protective glass of the Mona Lisa。 So dark the con of man。 The painting before her had no protective glass on which to write a message； and Sophie knew her grandfather would never have defaced this masterpiece by writing on the painting itself。 She paused。 At least not on the front。 Her eyes shot upward； climbing the long cables that dangled from the ceiling to support the canvas。
Could that be it？ Grabbing the left side of the carved wood frame； she pulled it toward her。 The painting was large and the backing flexed as she swung it away from the wall。 Sophie slipped her head and shoulders in behind the painting and raised the black light to inspect the back。
It took only seconds to realize her instinct had been wrong。 The back of the painting was pale and blank。 There was no purple text here； only the mottled brown backside of aging canvas and—
Wait。
Sophie's eyes locked on an incongruous glint of lustrous metal lodged near the bottom edge of the frame's wooden armature。 The object was small； partially wedged in the slit where the canvas met the frame。 A shimmering gold chain dangled off it。
To Sophie's utter amazement； the chain was affixed to a familiar gold key。 The broad； sculpted head was in the shape of a cross and bore an engraved seal she had not seen since she was nine years old。 A fleur…de…lis with the initials P。S。 In that instant； Sophie felt the ghost of her grandfather whispering in her ear。 When the time es； the key will be yours。 A tightness gripped her throat as she realized that her grandfather； even in death； had kept his promise。 This key opens a box； his voice was saying； where I keep many secrets。
Sophie now realized that the entire purpose of tonight's word game had been this key。 Her grandfather had it with him when he was killed。 Not wanting it to fall into the hands of the police； he hid it behind this painting。 Then he devised an ingenious treasure hunt to ensure only Sophie would find it。
〃Au secours！〃 the guard's voice yelled。
Sophie snatched the key from behind the painting and slipped it deep in her pocket along with the UV penlight。 Peering out from behind the canvas； she could see the guard was still trying desperately to raise someone on the walkie…talkie。 He was backing toward the entrance； still aiming the gun firmly at Langdon。
〃Au secours！〃 he shouted again into his radio。
Static。
He can't transmit； Sophie realized； recalling that tourists with cell phones often got frustrated in here when they tried to call home to brag about seeing the Mona Lisa。 The extra surveillance wiring in the walls made it virtually impossible to get a carrier unless you stepped out into the hall。 The guard was backing quickly toward the exit now； and Sophie knew she had to act immediately。
Gazing up at the large painting behind which she was partially ensconced； Sophie realized that Leonardo da Vinci； for the second time tonight； was there to help。
Another few meters； Grouard told himself； keeping his gun leveled。
〃Arrêtez！ Ou je la détruis！〃 the woman's voice echoed across the room。
Grouard glanced over and stopped in his tracks。 〃Mon dieu； non！〃
Through the reddish haze； he could see that the woman had actually lifted the large painting off its cables and propped it on the floor in front of her。 At five feet tall； the canvas almost entirely hid her body。 Grouard's first thought was to wonder why the painting's trip wires hadn't set off alarms； but of course the artwork cable sensors had yet to be reset tonight。 What is she doing！
When he saw it； his blood went cold。
The canvas started to bulge in the middle； the fragile outlines of the Virgin Mary； Baby Jesus； and John the Baptist beginning to distort。
〃Non！〃 Grouard screamed； frozen in horror as he watched the priceless Da Vinci stretching。 The woman was pushing her knee into the center of the canvas from behind！ 〃NON！〃
Grouard wheeled and aimed his gun at her but instantly realized it was an empty threat。 The canvas was only fabric； but it was utterly impenetrable—a six…million…dollar piece of body armor。
I can't put a bullet through a Da Vinci！
〃Set down your gun and radio；〃 the woman said in calm French； 〃or I'll put my knee through this painting。 I think you know how my grandfather would feel about that。〃
Grouard felt dizzy。 〃Please。。。 no。 That's Madonna of the Rocks！〃 He dropped his gun and radio； raising his hands over his head。
〃Thank you；〃 the woman said。 〃Now do exactly as I tell you； and everything will work out fine。〃
Moments later； Langdon's pulse was still thundering as he ran beside Sophie down the emergency stairwell toward the ground level。 Neither of them had said a word since leaving the trembling Louvre guard lying in the Salle des Etats。 The guard's pistol was now clutched tightly in Langdon's hands； and he couldn't wait to get rid of it。 The weapon felt heavy and dangerously foreign。
Taking the stairs two at a time； Langdon wondered if Sophie had any idea how valuable a painting she had almost ruined。 Her choice in art seemed eerily pertinent to tonight's adventure。 The Da Vinci she had grabbed； much like the Mona Lisa； was notorious among art historians for its plethora of hidden pagan symbolism。
〃You chose a valuable hostage；〃 he said as they ran。
〃Madonna of the Rocks；〃 she replied。 〃But I didn't choose it； my grandfather did。 He left me a little something behind the painting。〃
Langdon shot her a startled look。 〃What！？ But how did you know which painting？ Why Madonna of the Rocks？〃
〃So dark the con of man。〃 She flashed a triumphant smile。 〃I missed the first two anagrams； Robert。 I wasn't about to miss the third。〃
CHAPTER 31
〃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！〃
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。
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。 Call the numbers。 Warn the others。 Do not fail us in this。
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 promised； 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 promised。
〃Please answer；〃 she whispered in fear。 〃Where are you？〃
〃Hang up the phone；〃 a deep voice said from the doorway。
Turning in terror； she saw the massive monk。 He was clutching the heavy iron candle stand。 Shaking； she set the phone back in the cradle。
〃They are dead；〃 the monk said。 〃All four of them。 And they have played me for a fool。 Tell me where the keystone is。〃
〃I don't know！〃 Sister Sandrine said truthfully。 〃That secret is guarded by others。〃 Others who are dead！
The man advanced； his white fists gripping the iron stand。 〃You are a sister of the Church； and yet you serve them？〃
〃Jesus had but one true message；〃 Sister Sandrine said defiantly。 〃I cannot see that message in Opus Dei。〃
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。
All four are dead。
The precious truth is lost forever。
CHAPTER 32
The security alarm on the west end of the Denon Wing sent the pigeons in the