Smyth's debut adult fantasy murder mystery is The Undetectables.
At Tor.com they tagged five books featuring an unlikely alliance with a ghost, including:
Masters of Death by Olivie BlakeRead about the other entries on the list.
Listen, if I was the ghost of a problematic billionaire who then had a vampire real estate agent come in and try to sell the house I was murdered in from underneath me, I too would be both furious and dramatic about it. Tom Parker (THE FOURTH!) just wants to know why he died, and he certainly doesn’t want anyone living in his house. With Tom’s repeated attempts to thwart Viola Marek (the aforementioned vampire), she hires medium (and godson of Death) Fox D’Mora to help her get rid of Tom. I mean, help him move on to the afterlife. But when demons, a few angels, and a godling turn up, it soon becomes clear that much bigger things are at play, forcing Tom to decide whose side he’s actually on. And also, why do all the Tom Parkers in his family die such a horrible death?
--Marshal Zeringue