In this case I was giving eldercare to Linus Pauling while rebuilding both a classic railway steam engine and a starship propulsion system, somewhere in Alaska. I needed the train to transport the propulsion system back to the starship's landing site. Plus I had a detour to visit my old high school and make a presentation on life goals. I took Dr. Pauling on that trip.
Usually I understand the symbolism in my dreams, but this one seems to be a random shot from the wells of my subconscious. I would like to stay up past dinnertime tonight, though.