“The plant at Niagara,” said he.  “Gabriel, study this, now, as you never yet have studied anything!  For on your intimate knowledge of these plans—­which, by the way, have been obtained only at the cost of eight lives of our comrades, and through adventures which alone would make a wonderful book—­depends everything.  With all communications cut, and troops kept away, and our own people storming the works, you will yet fail, Gabriel, unless you know every building, every courtyard, wall and passage, every door and window, almost, I might say.  For the place is more than a manufacturing plant.  It’s a fortress, a city in itself, a wonderful, gigantic center to the whole web of world-domination!

“So now, to the plans!”

For hours, while Gabriel took notes and listened keenly, asked questions and made minute memoranda, Brevard explained the situation at the great Air Trust works.  The others looked on, listened, and from time to time made suggestions; but for the most part they kept silent, unwilling to disturb this most important work.

Carefully and with painstaking accuracy he showed Gabriel how the plant now embraced more than two square miles of territory around the Falls, all guarded by tremendous barricades mounting machine-guns and search-lights.  On both sides of the river this huge monster had squatted, effectually shutting out all sight of the Falls and depriving the people of their birthright of beauty, at the same time that it had harnessed the vast waterpower to the task of enslaving the world.

“From the Grand Trunk steel arch bridge up to and including the former plant of the Niagara Falls Power Company,” said Brevard, “you see the plant extends.  And, on the Canadian side—­or what was the Canadian, before ‘we’ absorbed Canada—­it stretches from the Ontario Power Company’s works to those of the Toronto-Niagara Power Company, including both.  In addition to having absorbed these, it has taken over the Niagara Falls Hydraulic Power and Manufacturing Company, the Canadian Power Company and half a dozen others, and has, as you see, established its central offices and plant on Goat Island.

“Here Flint and Waldron have what may be called a citadel within a citadel—­twelve acres of administration buildings, laboratories (in charge of your old friend Herzog, by the way!) and experimental works, including also the big steel chambers, vacuum-lined, where they are already storing their liquid oxygen to be turned into their pipe-lines and tank-cars.  This Goat Island central plant will be the real kernel in the nut, Gabriel.  Once that is gone, you’ll have ripped the heart out of the beast, smashed the vital ganglia, and given the world the respite, the breathing-space it must have, to free itself!”

“And if I don’t?” asked Gabriel.  “If anything happens to upset our blockading tactics, or if our attacking forces are defeated or our aeroplanes shot down, what then?”