The next day, I once again found myself in conference with my brother in the Stranger’s Room. We now knew what devilish designs Moriarty was working on. Which devices he had already made, what exactly they were for, which were completed and which would work, we could not say or predict. But he had a nations backing and had already killed several in his exertions. Mycroft closely examined my notes and drawing of the mechanisms illustrated in the Professor’s notes. “My God, Sherlock!” Mycroft exclaimed. “He is determined, has the backing and certainly the genius to possibly carry this off!” He had an agent sent for and turn these over, requesting certain departments set up a team he quickly defined from various units he dictated and requested they should go over them on a highly confidential classification. We needed immediate feedback and would require a briefing in three days. I stayed in town and spent time at the library trying to brush up on my sciences. I returned to the Diogenes Club for the appointed meeting to learn what they had found and help plan our next step. We had our agents brief us on Lord Rayleigh’s discovery concerning cavitation. They reported Lord Rayleigh first studied that inertial cavitation in the late 19th century when he considered the collapse of a spherical void within a liquid. When a volume of liquid is subjected to a sufficiently low pressure it may rupture and form a cavity. This phenomenon is termed cavitation inception and can occur behind the blade of a rapidly rotating propeller or on any surface vibrating underwater with sufficient amplitude and acceleration. Vapor gasses evaporate into the cavity from the surrounding medium, thus the cavity is not a perfect vacuum but has a relatively low gas pressure. Such a low-pressure cavitation bubble in a liquid will begin to collapse due to the higher pressure of the surrounding medium. As the bubble collapses, the pressure and temperature of the vapor within will increase. The bubble will eventually collapse to a minute fraction of its original size, at which point the gas within dissipates into the surrounding liquid via a rather violent mechanism, which releases a significant amount of energy in the form of an acoustic shock wave and as visible light. At the point of total collapse, the temperature of the vapor within the bubble may be several thousand kelvins, and the pressure several hundred atmospheres. The physical process of cavitation inception is similar to boiling. The major difference between the two is the thermodynamic paths that precede the formation of the vapor. Boiling is when the local vapor pressure of the liquid rises above its local ambient pressure and sufficient energy is present to cause the phase change to a gas. Cavitation inception occurs when the local pressure falls sufficiently far below the saturated vapor pressure, a value given by the tensile strength of the liquid. They had covertly contacted our finest mechanical engineers to discuss the mechanisms we had sketched, but it would take considerably more time to ascertain their functions and uses. Mycroft waited for all the briefing team to finish and depart, and then turned to me. “I have been given official active status by Sir Arnold, the current head of my old department. He offered me my old office, in fact he would have its current occupant evicted, but I told him I would work out of here or my own apartment if necessary. This will be my only concern, and I know I won’t be getting daily results from our investigations and studies. “We did not try to trail Moriarty when the lectures concluded as we know he would eventually return to his German bases. We of course searched the vacated house, but he had cleaned it thoroughly and we found nothing. “I will attempt to contact Jack Grimm in his deep clandestine cover without exposing him as our agent. I will update him on what we have ascertained and direct him to get us the current state on what progress the Professor has in his experiments and developments. “I fear we will once again have a long wait for events to mature before we will hear anything or even know what to do next.” “With official standing under the Kaiser, anything we contemplate against Moriarty and his company may induce dangerous international incidents just steps from declaring war. But a successful creation of a super weapon that could sink our battleships would turn the balance of power away from Great Britain. We must at all costs inhibit and stop Moriarty from completing his designs and prohibit any mass production of such weapons.” I once again feasted at Mycroft’s insistence that evening as his chef had arranged a special banquet to celebrate another club founder’s birthday. Life goes on despite growing evil across the channel. There was no more for me to do in London. I headed back once more to my retirement villa to await the call to action.