"We didn't have a hap'orth o' sense," added Dick gloomily.
By then the little party was close to the air ship. The watchman was within hail, and a few words from him satisfied the policeman.
"Sorry I bothered you, Motor Matt," apologized the officer, "but you're a dead ringer for that other chap--which is more credit to him than it is to you. He's your double, all right, and I hope you get back your letter."
The policeman went one way, the watchman another, and Matt led his chums to one side, where they could have a little private talk by themselves.
His face was grave as he asked them to begin at the beginning and give him all the facts, once more.
The ground was thrashed over pretty thoroughly, Matt putting questions from time to time that brought out even the apparently insignificant details. When the explanations were done a silence fell over the chums. Dick was first to speak.
"Keelhaul me," he observed, in deep contrition, "neither Carl nor I seem able to do a thing right when you're not around."
"I'm not finding any fault with you, pards," returned Matt. "Even the officer was fooled, so it is quite natural that you should have made the mistake. Give me that number on Prytania Street. I'd better hike right out there and have Townsend tell me what was in the letter."
"Townsend said the matter was of the utmost importance----"
"All the more reason why I should find out about it as soon as possible!"
"But he insisted that you wasn't to come to him until midnight, to-night."
"He don't know the letter has got into wrong hands."
"Sure he don't, but he's afraid the house where he is is being watched, and we were to tell you to come around the back way and knock at the rear door. I'm a Fiji if I know what's up, but Townsend was mighty particular that you shouldn't come until midnight."
"They say that every one has a double," he remarked, with a half laugh, "and it begins to look as though my double had shown up. This double-trouble was something I never expected to run into, but it's come and we'll have to see it through. Townsend didn't give you a hint as to what he wanted me for?"
"Never a hint," answered Dick. "He was mighty close about it."
"Well," decided Matt, "I'll be at that house in Prytania Street on the stroke of twelve, to-night. Let's feel as easy as we can about that letter, and go and get some supper."