This unnamed Slayer was active in the city of Tomar, Portugal in the late 1960's. She fought against the vampiric order of the Knights Templar and her last mission as the Chosen One was to collect an artifact called the Chalice of Magdoreth.
She chased down one of the Order and while she was interrogating him, his fellow knights arrived and surrounded this Slayer, killing her and draining her of her blood.
Her death activated Beryl McKenzie as the new Slayer. Beryl dreamt of her death and as the Slayer power entered her body, she knocked Lennox, a man with whom she was sharing a bed, into a far wall in the midst of the dream.