Hellfire Club: Darlington - Immortal Warriors, #2

The second book in the Hellfire Club trilogy. Nicholas Darlington has secrets, dark secrets, and although his attraction to Linny is unstoppable he knows if she discovers what he did in the past she won't be able to forgive him. And still he will do anything, even give up his life, to save her from the evil forces surrounding them. Linny has spent her life avoiding messy relationships with men. Darlington is messier than most but she can't seem to stay away from him.
The attraction between them grows stronger when they are taken to the Dark World and only have each other to rely upon. She is in love with her Regency rake but she must also learn to trust him. This book can be read as a standalone but may be confusing unless you have read Lorne first.