As soon as the lights went out, a Tesseract Portal bloomed to life behind Essex, casing new light over the dead computer panels. Sinister ripped open the disk drives in each one with no effort. He would take what data he could get, even if it wasn't everything S.H.I.E.L.D. could provide. He then fired a force beam into each one, blasting them into a sparking mess, for good measure. It would take the government clean up crews weeks to figure out what he'd taken, if at all.
"I know about Rogue, as I do all the X-Men, because I have encountered them before... and I had the Marauders trash their headquarters while I recovered pertinent data on all their members once. That was after you left," his voice, while still a bit bored, was laced with annoyance. "She is useful enough to my studies to desire to keep alive and out of the Governments' heavy hands. Just as you are useful enough to me at current."
The Tesseract Portal disappeared as the emergency lights kicked in and Sinister waved at the door, "I assume it was within the last ten minutes that this happened, else you wouldn't have been talking about her like she was here. I'd rather not have her or one of my favorite specimens of the mutant genome - meaning you - either crushed by a falling building because Magneto also needs a dire lesson in subtlty, or because S.H.I.E.L.D. field operatives become a tad too overzealous in the execution of their duties. Do lead on."