Baobhan Sith

Exhausted from reconstructing the Hellsing Organization's army following the Valentine Brothers' assault, and having been dismissed from a vampire attack by MI-5 (while also troubled by an ominous premonition from Alucard), Sir Integra Wingates Hellsing received an unexpected visit from Laura, her sister residing in the Essex area. The visit appeared friendly, but soon, strange events unfolded: Seras Victoria was restrained by Walter, Alucard had his first encounter with the masochistic vampire Incognito, and Integra herself felt unusually fatigued. She then realized, far too late, the sad truth: she was an only child, and the woman claiming to be her sister was actually a vampiric assassin.
"Laura Hellsing" is in reality a Baobhan Sith—a Celtic vampire often referred to as "the White Woman." Baobhan Sith typically wear long green gowns and are known to use hypnotism to ensnare their victims. This particular vampire stabbed Integra in the stomach before drawing her blood. Alucard (due to Incognito's boasting) realized what was happening, interrupted, and slew the beast before Integra was killed. As a result, Walter was released from the enchantment that forced him to restrain Seras, and both raced to Integra's aid.
However, because she was bitten, Integra nearly kills herself by stabbing herself in the neck to draw out the creature's taint from her body. Soon afterward, she was saved in a hastily-arranged operation by Dr. Trevelyan.