Along with his covens mates, Nelson was kidnapped by a german vampire named Amsel. In an unknown location inside an underground bunker, Amsel transformed him and his friends into vampires. After his newborn year, he and his friends went their seperate ways, deciding to meet back with one another a few decade later.
Bridget was also kidnapped, by a vampire named Creevey. She was taken all the way into Jersey before being turned into a vampire. Unknown to her, her coven had become too known by local humans, and the Volturi were forced to destroy them. Bridget only survived because she was out hunting while her coven mates were killed
Nelson and Brdget met around 1920 in Dusseldorf, Germany. When Nelson was reunited with his coven mates sometime in the 1940's, they're mates also came with them.