After a full day of classes, Lord Voldemort was in quite a decent state when he returned to Severus that evening.
Severus had already finished washing and was toying with the Time-Turner in his hands. Unless manipulated according to a specific method and infused with magic, it would not activate.
Yet under extraordinary circumstances—such as those few times in the past—the resonance of the world would still suck them directly into its pull, unrestricted by their distance from the Time-Turner.
Chapter 83