The first scene of Karen is when she is the hospital working as a hematologist. There her coworker is 'killed' by the vampire on the table. Karens profession helps the story due to her contributing to finding the cure of the virus or infection that she once had. She is an intelligent scientist by developing such a significant cure in such short time. This makes Karen feel as though she has an obligation to be involved in the plot and to help Blade. Karen is disgusted by the vampires throughout the movie but developes a relationship with Blade towards the middle/end. She stands up to Frost by telling him she doesn't care if he bites her because she already knew and had the cure for herself. Throughout the film Karen shows strength because she was defends herself and tries her best to fight back. Karen is used as bait to lure Blade in, which concludes they do have a relationship between each other. This is somewhat like the relationship in Let the Right One In where a friendship/relationship occurs between the vampire and a human. (Let the Right One In film) She frees blade from the iron cage he was held in and this shows she is somewhat fearless and does what is right even in a corrupted situation. Karen being so courageous doesn't flee or run away due to the tough and unusual circumstances. She then offers blood to Blade which shows her compassion towards him and shows she is a very strong women. When she is almost drained from her blood Karen still manages to kill another vampire with the pepper like spray given to her by Whistler. At the end of the film Karen offers Blade the cure that she had, this is showing she is thinking of his well being but she doesn't fully understand he needs to not take it and preserve his powers for the greater good.