Released in October 21, 2003, Batman: Mystery of the Batwoman was one of the final animated films released that was set on the DC Animated Universe and set on the same timeline as Batman: The Animated Series/ The New Batman Adventures. The film introduced viewers to a new "Batwoman", one heavily inspired in design by the costume worn by the Batman of The Future himself, Terry McGiness, aka Batman Beyond.
As the title notes, the identity of this Batwoman remains a mystery... Even to the deductive and brilliant mind of Batman himself. Wearing the symbol of the Bat, this Batwoman operates on a more ruthless scale, and takes down criminals and mob bosses like Penguin and Rupert Thorne without any moral restrictions like The Dark Knight and his allies practice. Ultimately, the plot thickens as Bane arrives, and the "identity" of the Batwoman is found to be quite the surprise.
Following the success of Batman: Mask of the Phantasm and Batman Beyond: Return of the Joker, a film set on the timeline of The New Batman Adventures was inevitable, and Mystery of the Batwoman does not fail to entertain and does a good job of showing how intrinsic and elaborate Batman's universe can be. The Batwoman mystery was a good way of introducing a version of the character to the DC Univcrse, not to mention tying things in to Batman Beyond in a certain degree. In fact, some years later would see DC Comics adapting that approach and bring a regular Batwoman with a "Batman Beyond" inspired design to regular DC Continuity, with Kate Kane becoming the modern AND New 52 version of Batwoman to date.
Aside from the main feature of this direct to DVD release, Mystery of the Batwoman also included a short silent film featurette called "Chase Me", which saw The Dark Knight going after his on-and-off love interest Catwoman in, as you'd expect, a grand chase. The jazzy and excellent musical score just punctuates the feeling of this great showcase right here.