At one point, this English-language Mexican production was the most widely-seen film from Juan López Moctezuma, 
the audacious actor-turned-filmmaker who shot this in between two other, more extreme outings, The Mansion of Madness and Alucarda. Those films have since overshadowed this one due to their cult followings via Mondo Macabro's DVD releases, while this one has largely languished in gray market DVD hell since its legit VHS release back in the '80s. In a surprising twist, the film was officially licensed from Code Red for a Blu-ray edition, a welcome development for a film that deserves more recognition.
Our tale fits comfortably within the numerous vampire films of the 1970s in which the supernatural elements are downplayed or even dropped entirely, with one of the most popular subjects along these lines being the infamous Countess Elizabeth Báthory. The real-life aficionado of virgins' blood was a popular inspiration at drive-ins at the time courtesy of films like Daughters of Darkness, The Blood-Spattered Bride, Countess Dracula, and Legend of Blood Castle to name just a few, while the fictional female vampire classic Carmilla often got tangled up with that scenario as well, most notably in The Velvet Vampire.
What we have here is essentially a 
modern day twist on the Bathory/Carmilla conventions in the form of Mary, an avant garde painter played by Cristina Ferrare. Mostly seen on TV shows after this, the former Max Factor model made headlines when her husband, car tycoon John DeLorean, went down in flames in a cocaine sting, and she went on to become a born-again Christian and a writer. Needless to say, all of that gives a certain charge to this film, her sole starring vehicle.
The film dreamily hops around through time and space as it charts the bloody descent of our anti-heroine, a vulnerable reluctant bloodsucker first seen finding refuge on a dark and stormy night running into another man also in the empty house hiding from the rain. As we quickly realize, she's a plasma-draining predator who uses her hairpin to draw sustenance from her male companions-- but there's something special about this one, a 
writer named Ben (Young). She genuinely seems to like the company of others which makes the inevitable carnage all the more potent, and on top of that she has to contend with another shadowy bloodsucking killer on the prowl (Carradine), whose connection to her only becomes clear gradually, and the lesbian advances of her agent, Greta (Rojo). Ben seems like he may be something special among her food supply, but is she ultimately destined for tragedy?
Perhaps because it straddles the line between drive-in sleaze and art film ambitions, Mary, Mary, Bloody Mary has been something of a tough sell, a possible reason for its elusive history on home video. An atrocious gray market DVD from 3D Circus attempted to convert the old VHS transfer to anaglyph 3-D, which turned out about as well as you might imagine. The Code Red Blu-ray is a major step forward, 
taken from one of the sole remaining film elements. It's imperfect of course with its share of scuffs here and there, but the transfer quality is light years beyond what we've had to date.
Some dispute seems to have arisen over the film's running time (with some pressbooks listing it as long as 101 minutes), but the 91-minute version here appears to be complete and includes that tasteless shark-whomping scene that leaves a pretty nasty aftertaste for most viewers. The sole extra is an entertaining 14-minute interview with producer Henri Bollinger, who chats about wanting to get into the horror film business (which always turns a profit), finding Moctezuma on Mexican TV, working with the frail Carradine, the artsiness of the original script, and the use of psychology to get Ferrare to do a nude scene while navigating around the possible intervention of DeLorean.
