Vampires exist. It is the duty of Hellsing, an organization backed by the British government, to hide this frightening fact and protect the blissfully unaware populace. Along with its own personal army, Hellsing also has a few secret weapons. Alucard, an incredibly powerful vampire, has been controlled by Hellsing for years. Although he dislikes being a servant to the Hellsing family, he certainly enjoys his job as Hellsing's vampire exterminator. Seras Victoria is a fledgling vampire and a former police woman. Although reluctant to embrace her new self, she is still a valuable member of the organization. Integra Hellsing, the current leader, is usually fully capable of fulfilling her duty, but lately, vampire activity has been on the rise. Unfortunately, the cause is more alarming than anything she could have imagined...
[Source: AniDB]
This OVA is a summary of the first three episodes of Hellsing, with the animation style of Hellsing Ultimate and following the events of the Hellsing manga.
Hellsing, a secret organization of the British government, have long been battling supernatural threats to keep the people safe from the creatures of the night. The current leader, Integra Wingates Hellsing controls her own personal army to eliminate the undead beings, but even her highly trained soldiers pale in comparison to her most trusted vampire exterminator, a man by the name of Alucard, who is actually a powerful vampire himself. Along with Integra's mysterious butler and Alucard's new vampire minion, Seras Victoria, The Hellsing Organization must face not only regular ghouls and vampires, but a rivalling secret organization from the Vatican, and Millennium, an enigmatic group of madmen spawned by a certain war over 50 years ago...
A bloody battle between monsters is about to begin, the dead are dancing, and all hell is singing...
[Source: Crunchyroll]
It is September 1944 and World War II is raging in Europe. To get an advantage on the field, Nazis are experimenting with artificial vampire technologies, they are still far away from achieving their initial goal, but even the intermediate stages of such researches are possessing a great threat to The anti-German coalition. In an attempt to stop the Nazi project and to protect England and The Allies current head of the Hellsing House, Sir Arthur Hellsing, is sending his best agents—Walter C. Dornes and Alucard—into German-occupied Poland where monstrous experiments are being conducted.