That was the night the first message came - but how and from whom no one knew. It was a warning of

Slow, Deliberate Murder.

Night after night the warnings kept coming. On the twelfth night, this was the message:

On the twelfth night of Christmas
Your true love sends to you,
This fatal dagger - this jeweled knife -
This finishing stroke to end your life.

And when they found the corpse, the dagger was buried deep in its back.