After communicating to Tremayne and Mazanoff the orders of Natas, he said to the latter—

"You will take Professor Volnow to present the Tsar's letter to the Admiral in command of the fleet. Fly the Russian flag over a flag of truce, and if he acknowledges it say that if the Lucifer is given up we shall allow the fleet to go on its way unmolested and without asking any question.

"The cruiser that has her on board must separate from the rest of the fleet and allow two of your men to take possession of her and bring her up here. The lives of the four traitors are safe for the present if the air-ship is given up quietly."

"And if they will not recognise the authority of the Tsar's letter, and refuse to give the air-ship up, what then?" asked Mazanoff.

"In that case haul down the Russian flag, and get aloft as quickly as you can. You can leave the rest to us," said Arnold. "Meanwhile, Tremayne, will you go down to two thousand feet or so, and keep your eye on that big cruiser a bit ahead of the rest of the fleet. I fancy I can make out the Lucifer on her deck. Train a couple of guns on her, and don't let the air-ship rise without orders. I shall stop up here for the present, and be ready to make things lively for the Admiral if he refuses to obey his master's orders."

The Ariel took the Professor on board, and hoisted the Russian colours over the flag of truce, and began to sink down towards the fleet. As she descended, the Admiral in command of the squadron, already not a little puzzled by the appearance of the three air-ships, was still more mystified by seeing the Russian ensign flying from her flagstaff.

Was this only a ruse of the Terrorists, or were they flying the Russian flag for a legitimate reason? As he knew from the experience of the previous night that the air-ships, if their intentions were hostile, could destroy his fleet in detail without troubling to parley with him, he concluded that there was a good reason for the flag of truce, and so he ordered one to be flown from his own masthead in answer to it.

The white flag at once enabled Mazanoff to single out the huge battleship on which it was flying as the Admiral's flagship. The fleet was proceeding in four columns of line abreast. First two long lines of cruisers, each with one or two torpedo boats in tow, and with scouts thrown out on each wing, and then two lines of battleships, in the centre of the first of which was the flagship.

It was a somewhat risky matter for the Ariel to descend thus right in the middle of the whole fleet, but Mazanoff had his orders, and they had to be obeyed, and so down he went, running his bow up to within a hundred feet of the hurricane deck, on which stood the Admiral surrounded by several of his officers.

"I have a message for the Admiral of the fleet," he shouted, as soon as he came within hail.