The short version is that two out of three of them ended up turned, and nobody was happy about it.

[ He's going to ask for the longer version. Trevor knows he is. ]

The long version- Walter couldn't die. Not for long. He'd been killed before, but he came back. Mathias had a solution - a thing made with alchemy called a Crimson Stone. It- let me remember. It's a kind of medicine, except it's a rock. It pulls all the bad shit out of a body and holds it. And it could do that with the vampirism, too. And it would be a dangerous relic, once that happened, but then they could just hide it somewhere- at the bottom of a big fucking hole in Wallachia, for example.