"Very well," replied Tremayne. "I will do as you say, and await developments with considerable interest. If there is going to be a fight, I hope you're not going to leave us out in the cold." "Oh no," replied Arnold. "You needn't be afraid of that. If his Majesty won't come to terms, you will smash up the war-balloons and then come and join us in the general bombardment. I see, by the way, that there are ten or a dozen more of these unwieldy monsters with the Russian force moored to the ground yonder on the outskirts of Cüstrin. It will be a little amusement for us if we have to come to blows to knock them to pieces before we smash up the Tsar's headquarters. So saying, Arnold increased the speed of the _Ithuriel_, swept round in front of the line, and communicated the same instructions to the captain of the _Ariel_. A few minutes later the _Ariel_ and the _Orion_ began to rise with their charges to the higher regions of the air, leaving the _Ithuriel_ and the one aerostat to carry out the plan which had been arranged by Natas and Arnold an hour previously. As the speed of the aerostat was only about twenty miles an hour against the wind, a rope was passed from the stern of the _Ithuriel_ to the cordage connecting the car with the gas-holder, and so the aerostat was taken in tow by the air-ship, and dragged through the air at a speed of about forty miles an hour, as a wind-bound sailing vessel might have been towed by a steamer. On the journey the elevation was increased to more than four thousand feet,--an elevation at which both the _Ithuriel_ and her captive, and especially the former, presented practically impossible marks for the Russian riflemen. Almost immediately over Cüstrin they came to a standstill, and then Colonel Alexandrovitch and Professor Volnow were summoned by Natas into the deck saloon. He explained to them the mission which he desired them to undertake, that is to say, the conveyance of a letter from himself to the Tsar offering terms for the surrender of the _Lucifer_. They accepted the mission; and in order that they might fully understand the gravity of it, Natas read them the letter, which ran as follows:-- ALEXANDER ROMANOFF,-- Three days ago one of my fleet of air-ships, named the _Lucifer_, was delivered into your hands by traitors and deserters, whose lives are forfeit in virtue of the oaths which they took of their own free will. I have already taken measures to render abortive the analysis which you ordered to be performed in the chemical department of your Arsenal at St. Petersburg, and I have now come to make terms, if possible, for the restoration of the air-ship. Those terms are as follows--