Untitled (Blood Sign #1), also referred to as “There is a Devil Inside of Me” was filmed, as part of a series referred to as Blood Signs, at the Intermedia Arts Studio at the University of Iowa in March of 1974. 
The film begins with Ana Mendieta standing in the center of the frame, facing a white wall, her back to the camera. A tray filled with blood sits to the right of her feet. She stands like this momentarily, her palms outstretched, facing the wall, before bending to her right and extending her right arm to scoop blood from the tray. She drags the blood up the wall in one long motion alongside her body, leaving a streak spanning her feet to her chest. Mendieta returns her hand to the tray repeating and darkening the streak; extending it into an arch above her head. Switching to her left hand, she drags blood down the left side of her body completing the arch. She dips her hand again darkening the stroke and then pauses to back up and take in the large outline on the wall encompassing her figure. Bending once more, she dips her right hand and brings it up in front of her face. With swift motions she spells out words within the arc. The words stack on top of one another. With her hand she spells out, “There is a devil inside me”, dropping to her knees just before inscribing, “devil”. The word “Me” is the darkest and the largest and she retraces over it with fresh blood twice before dipping both hands again in the tray. She stands and with a large swooping motion brings both hands down the sides of the arc, reaffirming the red that stains the wall, as she falls once more to her knees. She lays her hands in the blood again and plants them on the ground before her knees leaving her handprints as she stands and walks off to the left. The camera lingers on the wall for 20 seconds, the words dripping down between the finger streaks of blood. End film.
At the time when this film was created Mendieta was using blood as a central component to her body of work. The blood use, often read as a motif of sacrifice or purging of impurity, circles back to the idea of what Charles Merewether refers to as the “expenditure of the heterogeneous” in his essay From Inscription to Dissolution: An Essay on Expenditure in the work of Ana Mendieta. Looking at Mendieta’s work as a profound critique of the social sphere, Mendieta was interested in issues concerning social taboo, structures of domination, and transgression.  As a woman of color, displaced from her home in Cuba and subject her entire life to systematic structural violence, to represent the site of violence, eroticism and death was to represent the body of woman. Thus this film, as well as many of her other works of this period, focus specifically on sacrifice and transgression as relating to the female body.
Mendieta spoke once of the way in which she was perceived in the Midwest, stating that the people surrounding her looked at her as “an erotic being (myth of the hot Latin), aggressive, and sort of evil. This created in [her] a very rebellious attitude until it sort of exploded inside [her] and [she] became aware of [her] own being, [her] own existence as a very particular and singular being.” 2 As a Latina woman, for Mendieta to act out in aggression or anger would be to fulfill the stereotypes cast upon her, thus this type of behavior was largely discouraged. However, in doing so anyway and reclaiming that anger and aggression, Mendieta enabled herself to be powerful and transgressive. 
The possession that Ana Mendieta silently confesses to in this film is an assertion of this anger. The blood she physically mars the white wall with, serves as a metaphorical and literal basis of female vitality and sexuality and carries with it strong feminist overtones reminiscent of the period in medieval Europe when “primitive” rites of blood, fertility, and sacrificial healing were perceived as the work of the devil, and deemed unacceptable by the Catholic Church. As Chrissie Iles brings up in her essay Subtle Bodies, Mendieta’s “statement of possession” implies a conscious awareness that her emerging identification with and use of pagan symbols of female fertility (blood, earth, water, heat, fire and the silueta form itself) transgressed the patriarchal systems in place in Cuba, and the west in general, where it is believed to be “the blood of Christ, not the great goddess, that gives eternal life”. 1
In a text from 1982 Mendieta quoted Spanish philosopher Ortega y Gasset, she stated “To be a hero, to be heroic, is to be oneself.” Mendieta personal history as a woman of color in the United States was a driving force behind the anger and convictions that enabled her artistic processes.  “There is a devil inside of me” is a phrase that Ana continued to on at least two other occasions, it was found in her scratchpad as late as 1978, 5 years after this film was created. 
 Iles, Chrissie. “Subtle Bodies: The Invisible Films of Ana Mendieta.” Ana Mendieta – Earth Body: Sculpture and Performance, 1972 – 1985, Mendieta, Ana, Olga M. Viso, and Guy Brett. Washington, DC: Hirshhorn Museum and Sculpture Garden, Smithsonian Institution, 2004. Print
 Merewether, Charles. “From Inscription to Dissolution: An Essay on Expenditure in the Work of Ana Mendieta.” Ana Mendieta, Gloria Moure. Ediciones Poligrafa, S. A. and Centro Galego de Arte Contemporanea, 1996. Print
 ““The Battle Will Never End,” An Interview with Carmen Giménez Smith.” Interview by Lauren Fosgett. Http://superstitionreview.asu.edu/. Superstition [Review], n.d. Web. 18 Aug. 2014. <http://superstitionreview.asu.edu/issue13/interviews/carmengimenezsmith>.
 Lippard, Lucy R. “Who Is Ana Mendieta? Nobody Else” Who Is Ana Mendieta, Christine Redfern & Caro Caron, New York City: The Feminist Press. Print.