As Captain Archer prepares to lead a survey team to an uninhabited planet, Enterprise is suddenly hailed by a trio of aliens seeking refuge. The aliens warn Archer that a deadly neutronic wavefront is quickly approaching. After conferring with the crew, Archer surmises that everyone must take shelter somewhere protected in order to survive the storm's deadly radiation. Trip suggests that the one heavily-shielded place onboard that might suffice for the eight-day ordeal is the cramped quarters of the catwalk, the maintenance shaft that runs the length of each nacelle. Only one problem — the temperature in the catwalk can reach 300 degrees when the warp coils are online, so Trip will have to shut down the main reactor and set up a makeshift bridge in one of the catwalk compartments.