Mark of the Demon by Dianna Rowland

Blurb: Kara Gillian leads two lives, one as summoner and second as a BPD Detective. As a summoner she summons demons at night and as a cop she handles homicides and up till now she has been able to keep those two lives apart. Suddenly they collide when Symbol Man, a serial killer, starts killing again after a three year break and leaves traces of arcane behind. On top of that Kara accidentally summons a Demon lord, Rhyzkahl, who instead of killing her seduces her. Why?
Kara is determined to catch the the Symbol Man and she has the help the charming FBI Agent Ryan. As she gets closer to the killer she can't help but realize that its some one closer to her and as the number of killings increases so does her distrust of every one around her. Is every one trying to use her for their own means? Can she trust Ryan? Or should she trust Rhyzkahl?

Review: Mark of the Demon is the first book in Kara Gillian series by Dianna Rowland.
Dianna has created a world where there a some people with the gift of summoning. This gift is genetic in nature and can only be inherited.These people can summon demons in to this world and exchange favors. Demons in Kara's world are not of satanic origin instead they are a different specie from another planar. They are strong and divided into many levels according to their power and knowledge. 
Kara: Kara is a strong character with a bad-ass attitude and some great summoning skills. She  has finally graduated because she was able to summon a twelfth level demon. Though her character was strong and the author has done everything right Kara still left no impression on me. She was everything I expected and sometimes I wished she was not because it made her predictable.
As for her love interest both were almost unremarkable. Rhyzkahl was beautiful but a bit useless I think because he did not really help her out except when she was almost dying. Ryan was a bit better and liked him for most parts except for his weird mood swings that I did not get at all. May be the author was confused about what kind of personality she wanted him to have or may be its just me. I do not know. 
The case of Symbol Man was very interesting and the suspense was awesome. I could not deduce who the Symbol Man was until just before he was revealed. 
I think it has great potential and I want to check out the next book just to see where the author  leads it.
                                                                                                Yours sincerely,
                                                                                                          Ashi.