In Tracy Letts's nightmare Bug, Lance Marshall inhabited his character so fully, he put us on the edge of our seats out of sheer panic — and fascination. As the story went, way off-center skinhead Peter appeared in the squalid apartment of down-and-out Agnes, needing a place to crash. Suffering from delusions and medical experiments, this Gulf War vet — or so he claimed — was as screwed up as one could get. Yet Marshall revealed Peter's internal scars gradually, allowing the horrors to intensify. Those downcast eyes, ever-shifting, became beams. His doper shakes became paroxysms. The bugs were in there; they were growing under his skin. He was infested with them, with something deep and terrifying. He scratched and clawed at them. Love took a wicked-wrong turn as Peter zoomed into psychosis, dragging Agnes down with him. Marshall kept us mesmerized by this over-the-top, ultramodern Grand Guignol. He never let up. His unbearable pressure, nicely calibrated through director Ananka Kohnitz, reached full boil and blew the roof off Theatre Southwest. And that was before he wrenched out his tooth with a pair of pliers.