"Hello, Dawson," he answered in English, trusting that the men at the next table had not noted his slip. "Sit down and have something? Rotten weather, isn't it? And not a lead in sight. These Mexicans seem to be afraid to enter into any contract that ties them up more than a year—and eighteen revolutions can happen in that time."

As Dawson seated himself, Stewart gave him a hasty sign to be careful. Watching the Mexican and his companion out of the corner of his eye, he steered the conversation into harmless channels, but a moment later the pair at the next table called the waiter, gave some whispered instructions, and left.

"What's the matter?" asked Dawson.

"Nothing—except that I involuntarily registered a knowledge of Spanish when you spoke to me just now, and I've spent several months building up a reputation for knowing less about the language than anyone in Mexico City. As luck would have it, there was a couple seated at the next table who were giving me what sounded like the first real dope I've had since I got here. I'll tell you about it later. The question now is to get back to the hotel before that precious pair get in their dirty work. A code message to Washington is all I ask—but, if I'm not mistaken, we are going to have our work cut out for us on the way back."

"Scott! Serious as that, is it?" muttered Dawson. "Well, there are two of us and I'd like to see their whole dam' army try to stop us. Let's go!"

"Wait a minute," counseled Stewart. "There's no real hurry, for they wouldn't dare try to start anything in the open. In case we get separated or—if anything should happen—wire the Department in code that a vessel with a Spanish name—something that begins with 'Eep'—has cleared Hamburg, loaded with guns and ammunition. Expected at Vera Cruz about the twenty-first. Germany's behind the whole plot. Now I'll settle up and we'll move."

But as he reached for his pocketbook a Mexican swaggering along the sidewalk deliberately stumbled against his chair and sent him sprawling. Dawson was on his feet in an instant, his fists clenched and ready for action.

But Stewart had noted that the Mexican had three companions and that one of the men who had occupied the adjoining table was watching the affair from a vantage point half a block away.

With a leap that was catlike in its agility, Stewart seized the swaggering native by the legs in a football tackle, and upset him against his assistants.

"Quick, this way!" he called to Dawson, starting up the street away from the watcher at the far corner. As he ran, his hand slipped into his coat pocket where the small, but extremely efficient, automatic with which all government agents are supplied usually rested. But the gun wasn't there! Apparently it had slipped out in the scuffle a moment before.