She flings herself about demonically in heels while clinging to a carbon fibre violin, dispelling the notion that the rock violin is an awkward stage instrument.
The white walkers have been around since scene one, of course, but that's a little different -- they're some unknowable force, demonically powered, inhuman to the core.
When he makes his gruesome discovery of the patient's hidden wound, it all rose to a climax, with a demonically thrumming dulcimer and hysterically squeaking clarinet.