my dear Frank . when you hear this , I shall be dead . it is now ten o&apos;clock and I am quite alone in the laboratory . I have fastened the door and am now seated before the recorder . Frank , I have invented a weapon which I call liquid glass . the atom bomb causes death by fire . my invention causes death by freezing . liquid glass is in the form of small crystals . five of these crystals enclosed within a glass cylinder are sufficient , when dropped from a plane , to reduce the land beneath to a thick crust of ice . all people caught within the belt are frozen to death instantly . therefore , should a free nation be threatened by another , they can meet the menace of their enemy &apos;s atomic fire with the introduction of a new ice age . I have placed my formula in a secret cache for greater safety , for I fear , Frank - I very much fear - that I am shadowed and that some person may have more than a faint inkling as to what I have brought into being . have you ever heard talk concerning three men who are known as the terrible three , who have managed so far to elude capture . their field of operation is world wide , but there is a rumour that they are at present in the States . these three men have the reputation of possessing superb nerve and cunning . I know many inside stories of the happenings under cover within Europe . the merest glimpse of a man &apos;s face is sufficient warning to the initiated , but I have no proof . therefore be on your guard . now for your instructions . snatch a moment when the house is unoccupied - but do n&apos;t send the servants out too obviously - then go upstairs to the attic . in the second room you will find a line of pictures resting against the wall . choose Psyche and Pan , and take off the back . between this outer covering you will see a sealed packet . the words liquid glass are written upon the envelope . take it to Professor Slade , Carmel , Balfour Crescent , New York . once it is in his possession your task is completed . but whilst this operation is in progress I beg you to use the utmost discretion . trust no one ; neither a friend nor a beloved one . remember - you will be holding dynamite . there remains nothing more for me to say , I think . thank you , Frank . I know you will do it &amp;hellip; well . the tape ran on soundlessly until Frank , breaking the spell , pressed the fast-wind switch . now he understood the Professor &apos;s agony of indecision . this was , indeed , the answer to the atomic bomb , but what a fearful answer . he felt the mantle of responsibility descending upon his own shoulders . lifting off the tape , he hesitated over what he should do with it . he could of course remove the message , but he naturally preferred to carry it with the sealed packet to Slade . in the meanwhile where could he keep the tape ? he dared not leave it about , so he decided to carry it perpetually around with him . this point settled , he reflected he wanted to take a shower . when he &apos;d tied the belt of his bathrobe he slipped the tape into the pocket . within the shower compartment his brain ran riot , in company with the falling jets of water . he ran his fingers through his hair while he figured . I only need the right opportunity to snatch the packet , then carry it to New York and my part is over . when he returned to his room he found he was again looking around for the unexpected . it &apos;s too darned easy to let your imagination take the reins , he admonished himself . he did not really believe Zinnerman &apos;s secret was known . he did n&apos;t credit the Professor &apos;s notion that he &apos;d been trailed . no - just a sick man weaving fantasies , and you &apos;d better watch out for yourself , he warned , or you will be starting on the same road , too . he turned the key softly in the lock for the first time since he &apos;d slept in this house . half an hour later Frank lay on his bed in the inner room . he was smoking and flicking over the pages of a book . the tape now reposed beneath his pillow . it seemed to him that the night was endless . had he the least hope that he &apos;d sleep ? at length he laid aside his cigarette end in a silver tray and turned out the light . in retrospect he saw again Zinnerman &apos;s face close to his , and felt the Professor &apos;s hands gripping his shoulders . he relived the scene in the laboratory , then he drifted into sleep . what was that ! Frank sat up and listened . he heard a sharp click-click . he switched on the table lamp , swung his feet to the floor and reached for his robe . is anyone there ? he called . in the next room he groped for the light button and flooded the apartment with illumination . he had to wait a minute to adjust his own vision . then going over to the door he released it . the passage was empty . is someone there ? he queried . no one replied . no sound disturbed the heavy silence which now ruled the house . he closed his door . his watch registered two o&apos;clock . he extinguished the lamp and pulled back the heavy drapes from the window . the dark sky was lit by a silver moon boat . the trees were scarcely discernible ; a serene autumnal scene . he wandered back into his bedroom . here , he shook out a Stuyvesant from the packet on the small table and used his lighter . seated on the side of the bed he commenced to evolve plans for the morrow . chapter two . frenzied web . the new day proved a whirlpool of activity . Frank had to cope with dozens of letters , attend to callers , and take each phone call which occurred about every fifteen minutes . at mid-day Benn entered Frank &apos;s study carrying a tray . Frank wanted only a sandwich and a glass of milk for luncheon , and as the butler deposited the tray upon the desk he asked if he might slip out for half an hour . sure , Frank agreed absently . then as the man departed realisation dawned . with Benn removed , the house would be virtually empty . the other two servants had gone out a while since . Johnson was in the laboratory with sufficient work to occupy him for an hour at least . he &apos;d been very late the previous night and was trying desperately to make up the time he &apos;d lost . he had hinted to Frank that he &apos;d had a lot of fun and consumed quite a number of highballs . possibly he &apos;d been responsible for the noise that had woken him , Frank had decided ; and now within a short span of time he would have his chance within his grasp . he waited until he heard the front door slam ; made a quick check to ascertain that the house really was untenanted , then he swiftly mounted the stairs which led to the next storey . he opened a door . the first room looked rather eerie in the faint light filtering in from the lowered shades . Frank crossed to the second door and turned the handle . there were several pieces of furniture stored in here . resting against the opposite wall were a row of pictures , gilded frames turned towards the wall . he examined each in turn , then as the fifth picture passed through his hands he knew with quickening pulses that this was the one he sought . a lovely study of the kneeling Psyche imploring the aid of Pan who , in his genial way , was apparently giving advice to the stricken girl who had lost her lover through her own imprudence and mistrust . Frank produced his penknife and gently attacked the back of the picture . he was aware that the task must be delicately done . he owed that to Zinnerman . at length it was finished and the square piece of plywood fell away . there , resting against the canvas was a small sealed packet , measuring not more than six inches by four . he lifted it up and read liquid glass inscribed in the Professor &apos;s neat script . he slipped the package into his pocket , and then commenced the work of restoring the picture in as perfect a condition as before . when he was at last satisfied he came away and descended the staircase . he strode swiftly into his room - and stopped - eyes riveted upon his black jacket lying across a chair . within the right hand pocket reposed the tape . how could he have been so careless as to leave it here ? but it was all right , he reflected the next instant . the dwelling was deserted . nevertheless his conscience troubled him as he slid his hand into the pocket to recover it . the tape was not there . he explored the left side pocket , and again drew blank . where was it ? he was certain beyond a shadow of doubt that he placed it there this morning . his gaze flashed around . there was a tape on the recorder which he &apos;d left bare last night . he bounded over to the machine . the tape was a quarter wound off . he switched on , fast-wound , and pressed the playback button . with an indescribable shock he heard Zinnerman &apos;s voice saying the first words of his message . Frank stopped the machine and stood taut . someone had been in this room during his absence . for a moment he could not move as realisation flooded his brain , then he fled into the corridor . who is there ? he shouted . his voice echoed - and there was no reply . he made a swift search of the first floor rooms and rushed down the stairs to explore the rest . he found no one . he ran across the lawn to the laboratory and threw the door wide . Johnson , who seemed to be terribly busy , glanced up at him in an apparently startled fashion . hello , Frank , he greeted . have you come to give me a hand ? that sure would be acceptable . Frank ignored this . did you come into the house just now ? he demanded abruptly . Johnson ruffled up his hair . who , me ? he exclaimed . good God , no . I &apos;ve far too much to do , but if you were thinking of brewing coffee , I &apos;d love some . better make it black though . I went out on the town last night . Frank stared at him , trying to read within Johnson &apos;s eyes whether he was speaking the truth or not . then Frank withdrew , closing the door after him . he went swiftly back up to his room and removing the tape , slid it into his pocket . he thought wretchedly , how much harm have I caused already ? it was abundantly clear to him that an intruder had been here , but just how far that person had advanced in knowledge was open to speculation . he might only have had time to hear a part of the tape , or - he was now as wise as Frank was . how could he tell ? there just was n&apos;t time to waste in self-reproach for this criminal carelessness on his part . there was only one thing to do - think fast , and decide just how the situation should be remedied . he moved over to the window and looked down upon the garden . Johnson , of course , was the most probable candidate for the unknown intruder . if only there was some way of checking up on him . the tall trees stood sentinel below dressed in their garlands of russet leaves . autumn . the loveliest season of the year . a figure was crossing the stone courtyard below . Benn , returning from his errand no doubt . Frank turned away . then a new line of thought arrested him . could this have been the work of a stranger ? a person Frank had never seen ? a creature well adapted in the art of a quiet unnoticed entry and a swift melting away afterwards when the task had been completed ? a saboteur perhaps ? one of the terrible three ? but let him deal with facts known . however much his enemy had learned there was one point he could n&apos;t be aware of , namely that Frank had already secured the packet . 