Our liaison on the ground was trying to help us land our futuristic spy jet thing, but we had gone too far south to land on any of the roads, so she was jury-rigging some thing to let us land on the train tracks that were there. However she was also a traitor, and had switched her work van (a UPS scale van) for an exact copy, except that it mistakenly didn't have the same radio transponder as the original truck. So between that and some other hints, we knew something was up, and landed elsewhere so we could spy/capture our former friend. We were around this weird kind of metroplex mall thing place, kind of like if the domed theaters they have down here were a whole mall. We were stuck trying to disarm some kind of beacon or buoy or mine thing our traitorous friend had left, but the device was authenticated with a Crystal Method song. We would have to reproduce it. However one of our party was worried that the high-speed trains going through (kinda like the Half-Life 2 trains) would be endangered by the radio waves emitted by an mp3 player (leaving aside that I don't know that we had an mp3 player among all the awesome spy gear we had on us). We were running out of stall time so we were then trying to fall back from the device while radioing that we couldn't find her due to her missing transponder, but we mistakenly almost went closer to her, which I should have known because I'd seen that scene previously in the dream.
In retrospect he was obviously in cahoots. With all the other devices around, the emissions of an mp3 player would be lost in the noise. Luckily it wasn't the guy played by an amalgamation of Simon Pegg and Alton Brown; that would have been tragic.