Through an accidental digital flicker on an old shortwave radio frequency, the three of them connect. They realize they aren’t just monitoring different things; they are listening to the same heart from three different chambers. The Turning Point

stops every clock in his village, bringing a terrifying, beautiful stillness to the mountains.

They discover that the "Heart" isn't a physical place, but a state of synchronicity. To "restart" the heart, they must perform a simultaneous act of silence.