Like Smoke (Viking, #1)

Trygve is used to being on his own. His wife rejected him when he became a draugr around the year 800, and he hasn't trusted anyone but his best friend, Thorvald, since then. He lives and works alone, and he has no intentions on changing that. Then he meets Isaac. Isaac's life has been rotten-he was kicked out by his parents when he was sixteen, he was kidnapped from the streets at twenty, and he spent the last eight years chained to a wall and being abused. So when a tall blond man, appears out of thin air and kills the man who's been torturing Isaac for so long, he begs for death-or to be taken away. Trygve knows he should dump Isaac in a hospital and go back to his solitary life, but Isaac needs help, and for some reason, he seems to trust Trygve, so Trygve lets him stay with him. Neither of them expects their unlikely friendship will become more, and they take things slowly, for both their sakes. But someone is after Isaac, and Trygve knows he will do anything to protect the first person he's loved in more than a thousand years. Even if that means killing people he's not being paid to kill.