THFH

The steady dripping echoed around her room. She had grown used to the sound, and actually relished the leaky faucet. It drew comfort, a strange thing to find comforting, but at least she knew she was alone. Anyone else would go crazy. Some people thought she already had.
She didn't care what they thought.
She was ready.
And they weren't.
She quickly ran around the room, gathering supplies such as candles, a large, purple, triangular mat, a small knife, and a random bird from her cage of canaries. Humming to herself, she snapped the bird's neck and sliced down the middle of the bird, exposing the ribs and insides. She ripped the ribcage open and carefull drew out the still warm heart.
"Yes....This is what He needs....." she breathed. Placing the candles around the edge of the purple mat, the lady smiled maniacally. The heart was placed in the center of the mat, where it lay silently. Then, quickly, it began to beat in time with the with the leaky faucet.
Drip, thump.
Drip, thump.
At the end of six thumps, the heart disappeared altogether.
"Master?" She said, quietly. A voice whispered around the room.
"Yesssss. It issss I..."
"Master, You called me!"
"Ah, yes.....you know what to do...."
"Yes, but why did you call me?"
"You must write a note..." The lady paused, thought, then spoke again.
"What should I write?" This time the Master paused.
"Write four letters."
"What letters, Master?"
"Only these..." The lady paused and waited.
"THFH."