Dagger to the Heart
I had been stabbed in the chest ten times, and I was used to it this time.
Cain moved quickly and steadily cut through my chest despite his shaking hands, not leaving much flesh or blood.
Soon, he chanted an incantation which protected both hearts, and swapped their places.
When his heart entered my chest, my whole body shuddered, and my head suddenly felt clear.
As my chest rapidly closed itself, I suddenly realized that things I didn't understand before were abruptly clear.
Beside me, Cain put my Bleeding Heart that was beating relatively slowly into his chest.