No trifling with me! I never jest! There is grim purpose in all I do; and I warn you that you do not thwart me. Take care, for the sake of others if not for your own.

– Bram Stoker

Dracula, Chapter 10. Van Helsing’s angry reaction to Lucy, when she is not happy with him putting garlic in her room and around her neck, accusing him of joking with her. He tells her the garlic flowers are medicinal and during an exchange with Dr. Seward, Van Helsing does not deny they may be a "spell to keep out an evil spirit." He also tells Lucy not to open her window or door that night.