Entering his office using the quick, short steps that staff officers often use when going about their duties, Underwood made a sharp turn to the right. He avoided a collision with a spec four only because she stepped back at the last minute when she saw him coming. He slowed his pace only when he reached the chief of staff’s door. Sticking his head through the open doorway, he rapped lightly on the wooden frame. “Sir,” he announced as Colonel Felden looked up from the staff paper he was busily marking with a red pencil, “all the principals are in place.”

Felden threw down the pencil. “Do we have an ETA on Iron Horse Six?”

Underwood flashed one of his self-confident smiles that Felden always saw as a smirk. “Five minutes, sir.”

“Very well, I’ll be right there.” Felden didn’t bother to remind Underwood to make sure that there were two cold diet colas waiting for Iron Horse Six at the conference table. Underwood knew better than to overlook such an important item.

Iron Horse Six was Scott Dixon’s unauthorized radio call sign. Official call signs were a series of randomly selected letters and numbers that changed daily. These call signs, along with other important signal and command and control information, were complied in a pocket size booklet known as the communications electronics operating instructions, or CEOI. Since the bulk of the information in a CEOI was classified, it had to be locked up and accounted for when not in use. American soldiers, who were no different from any other soldiers throughout the world or the ages, often found it bothersome to draw their CEOIs when going out to the field for a quick training exercise. Even when they did have their assigned CEOIs with them, it was sometimes a nuisance to look up or use the proper call sign, especially when the call signs changed at midnight or in the middle of a tactical situation. In those cases many a commander and soldier found it easier, and quicker, to use their unofficial call sign to identify themselves or call another station whose authorized call sign did not immediately come to mind.