Sealed in Blood starts at a science fiction con with all the wonderful insanity that goes on at one of those events: Wookies-Amazons-green skinned Martians-vampires, buttons, people with diverse opinions arguing impossibilities such as civil rights for Bigfoot, folk singing, and the costume Masquerade.
Nigel Jamison, a vampire and a psychology professor at Berkeley, arrives at the con looking for Keith Brewster, a sometime author, who claims to have pictures of a genuine winged alien. Nigel suspects that the pictures are of one of his species and plans to steal them before they can be made public. Nigel enlists the aid of a fellow conference goer, Sherri Hudson, with a bit of hypnosis and a lot of good old-fashioned sex appeal. Who wouldn't fall for a tall, handsome stranger wear a cape and white ruffled shirt who might be Frank Langella playing Dracula, or D'Artagnan without the sword, or Rudolf Rassendyll, straight out of The Prisoner of Zenda.
Nigel Jamison is still trying to recover from his addiction to a former lover and donor, Denise, and he is not about to make the same mistake a second time, no matter how healthy and good smelling Sherri Hudson is. He is just going to use her to help get the pictures.
Sherri stands lookout while Nigel searches Brewster's hotel room. When Brewster returns sooner than expected, Sherri stalls him until Nigel can slip out of the room and up behind Brewster. In a move suspiciously like a Vulcan neck pinch, Nigel renders Brewster unconscious and steals the photos. When Nigel sees the pictures, he is shocked--they are of his half-sister Laura and she is participating in a Black Mass.
Sherri worried about the unconscious Brewster calls his room, only to have the phone answered by the police. Brewster is dead, his room ransacked. At first, Sherri thinks that Nigel did it, but he convinces her that he had no reason to go back and kill Brewster. Someone else must want the pictures, and Nigel is convinced that someone is holding his sister against her will.
Sherri flees home, feeling safe and well out of it until she gets a phone call threatening her unless she turns over the pictures, pictures she doesn't have. Angry and a little bit terrified, Sherri tries to call Nigel, but he is in Los Angeles following up a clue they
