With Chris covering the doctor, who, despite some romantic notions, was in no condition to try much of anything even if he had the gun, Sandoval tried on the large suit. It was clear even without the helmet that the fit was ridiculous, and with that helmet he would barely be able to balance himself. “No use,” he muttered. “It’ll have to be the other one.”

Dr. Karen Cline sighed. “Yes, I agree. But you haven’t much reserve. You’ll be O.K. for the trip, but if you have to make a boost, it’ll be touch and go.”

“We are traveling in time!” Sandoval exclaimed. “Why do we need much at all?”

“Time is relative. All other things being equal, time breaks first, so you’ll go back. But the journey takes time because it requires a steady power supply. Inside the suit, it’ll take time to get there at the same rate as power is being supplied. To 1875, it’ll take, oh, forty minutes or so. Once there, the reality of the suit is the only link you’ll have with the present. The suit must be kept energized from here, using full power, or you’ll nightside. That means we can’t add anything once you’re on your way. The internal suit charge will remain at where it was when you left, minus the power required to get you there. Even then, it’ll deteriorate as time will try and throw it out. The effect is progressive. Twelve days is all it’s safe for Chris, fourteen for you, in any one time slot. And we have to hold this installation for the exact same amount of time you spend back there, because we can only send power at the normal clock rate.”

“In other words, the shorter the better,” Sandoval said. “Well, I depend on you. All of you. You know the stakes.”

Sandoval quickly got into his suit, then took the rifle while his companion donned hers. “Get Clarence in here,” he ordered, and Cline left.