"So Dr. Freeman, I understand you came here looking for answers; soon, you will get those answers" the G-Man said while turning around. "Some of them will be free of my usually cryptic responses; some, you will find beyond where the Borealis's drydock lies. I find that some answers are most potent and believable when they are corroborated by other sources. To that end, continue on and you will discover what you need to know."
The G-Man disappeared, making Gordon feel free to move down the drydock. He came across a locked elevator shaft which was promptly opened by GlaDOS. Gordon entered the elevator and descended to a large antechamber with several test chambers. Each test chamber contained or had contained an object or creature; they also had a pre-recorded message from Cave Johnson play on entry.
Chamber #1: A room with some splotches of white conversion gel and a yellowish-orange rock. "We found what appears to be a meteorite crash site with a whole load of these crystals and basically took back all of them. We did all sorts of tests with this crystal; dropped it in various chemicals, shot it through portals, a test subject even tasted it. So far, nothing seems to make it react. A highly unusual, but potentially highly beneficial material if we only knew what to use it for.
Chamber #2: A empty chamber with what appears to be electric blast marks on the wall. "We made history in science yesterday when we decided to run one of our mystery crystals through an Anti-Mass Spectrometer. A creature we have identified from its rantings as coming from the planet Xen had been teleported in. Only one scientist was hurt from this experiment; she was too mesmerized by the formation of the portal to get out of the way of the miniature Resonance Cascade."