User blog comment:JAlbor/Dawnguard: What Everyone Should Know/@comment-4324788-20120630234138/@comment-3486380-20120701012434

Side with the vampires

Dawnguard Vampire Hunters will find you and attack you like the hired thugs.

you can easily loot a crossbow

or when you meet isran at fort dawnguard for the first time he will give you a crossbow just let him finish talking (this doesnt mean you're an offical member of the dawnguard you can still side with the vampires)