I mark this cross of blood upon you as a sign that I do it.
5 seconds sound clip from the A Tale of Two Cities (1938) classic radio drama series episode.
You can hear this line at 00:05:26.880 in the radio play.
Quote context
[...]
- I tracked him here and last night I climbed in.
- A common dog, but a sword in my hand.
- I made him draw and fight with me.
- Common dog that I am, where is he?
- I mark this cross of blood upon you as a sign that I do it.
- He put his hand to the wound in his breast and with his forefinger drew a cross in the air.
- I congratulate you, my brother.
[...]