 Which isn't something the guard did?
There is one fact no sane man can quarrel with ... You will, you know, so why quibble about it? At least, you always have ... or do ... or will. Yes, it'll be pretty obvious it must be a time machine. Doesn't hurt, and when you pull your arm back, you're still sound and uninjured. "Maybe it's no dimension—or it might be the fifth; if you're going to skip over the so-called fourth without traveling along it, you'd need a fifth. That means you either carry a small time field with you, or you are catching a small increment of time from the main field.
 help him carry the atomic generator to the time machine
 help him carry the atomic generator to the time machine  help him find the atomic generator  hand him the patent and other helpful information  give him time to take it out of the building