Just as he started to follow out this idea, Slippery stepped around the corner, and after he once more warned the lad not to falter in shooting to kill, he gave Joe a spool of fine copper wire to hold and when the surprised boy wished to know the reason, he showed Joe where he had the other end of the same wire twisted about his wrist, and cautioned him to hold it taut and that every time he gave the wire a sharp pull the boy should answer with the same signal, and that if he saw anyone approaching several sharp pulls should be the danger signal.
Then he again left the lad, and whenever he tugged on the wire Joe answered with the agreed signal, and by this simple means Slippery had not only forced a harmless boy to do dangerous outpost duty, and was assured that he was always on guard, but what was most important, he had a noiseless danger signal that, even should the boy fail to kill somebody, he would thus notify the robbers that all was not well and give them plenty of time and a far better chance to make their getaway than the boy himself had, especially if he "shot to kill", as he had been commanded to do, which would have meant a long term behind the prison bars if not a trip by the route of the hangman's rope.
While Joe had thus been forced to become their involuntary accomplice, the two yeggs pried open the rear entrance of the store, and then Slippery worked at his profession of safe blowing.

When all had been made ready to explode the charge, they carried the satchels with their tools out of the store and placed them in the buggy and made everything ready for an instant escape.

Boston Frank unhitched the horse and held it by the head, while Slippery went back to the store, lit the fuse and then stood at the rear door until an explosion, which seemed to tear the store asunder told the waiting yeggs that the moment to commence their dangerous harvest had arrived.

While Boston Frank had trouble to quiet the madly plunging, frightened horse, Slippery dove into the store to emerge again an instant later choking, sneezing and almost blinded just as if he had dynamited a box loaded with powdered red pepper instead of a common fireproof safe.

Foiled in stealing the contents of the safe, amid awful curses, he climbed into the buggy and called to Joe to jump upon its rear, and while they heard all around them loud calls and even pistol shots of the farmers, who had been aroused out of their slumbers, Boston Frank turned into the highway leading back to Dixon and the race for their liberty commenced.
They dashed down the wagon road at top speed, Boston Frank ever urging the horse on to greater efforts, as in speed lay their only salvation.
Passing the first farm house which fronted upon the wagon road, they could see by the light cast by a lantern that stood beside him upon the porch, a man dressed in his night robe raise a revolver and after taking a careful aim at the approaching buggy, just as they were in line with him, discharge point blank in quick succession its six messengers of death into their midst.