"I'm sorry." I didn't ask to show up here. I didn't mean to-- But that's not going to help. Even apologizing isn't going to do much. If she's damned all of Barrayar, nothing she can do now can fix it. "I--I don't know how it spreads. Maybe I didn't bring it with me."

But even with an abbreviated science education, she knows how unlikely that is. Everyone thought it was airborne at home. Maybe waterborne, but it spread so quickly--and now another planet might end up overrun with walkers.

"I'm sorry," she says again, her nails digging into her palms. The horror in Byerly's face looks like it belongs someplace else; he's suddenly a different man, staring at her like he just discovered the Cetagandans weren't Barrayar's biggest threat after all.