Another round hatch was let into the steel wall here, and it was ajar, with an extension cord running into it from an outlet on the wall. T.R., with help from a crew member, shoved on the hatch, which was slow to get moving but then glided serenely. It opened inward. Saskia could see that it was designed to withstand internal pressure, like a bung on a barrel. The space beyond was illuminated well, if harshly, by an ordinary work light plugged into the extension cord. T.R. bent over and stepped through, beckoning Saskia to follow.