- Series: Harrison Investigations Series Record # 26816
- Sub-series of: The Ghost Series
- Series Tags: paranormal suspense (8), paranormal romance (3), ghosts (2), horror (1), serial killer (1)
- 1 Harrison Investigations
- 1 Haunted (2003) by Heather Graham
- 2 Ghost Walk (2005) by Heather Graham
- 3 The Vision (2006) by Heather Graham
- 4 The Dead Room (2007) by Heather Graham
- 5 The Death Dealer (2008) by Heather Graham
- 6 Unhallowed Ground (2009) by Heather Graham
- 7 The Presence (2004) by Heather Graham
- 8 The Séance (2007) by Heather Graham
- 9 Nightwalker (2009) by Heather Graham
- Nightwalker (excerpt) (2009) [SF] by Heather Graham
- Harrison Investigation Series: Volume 1 (2018) [O/1-3] by Heather Graham
- Harrison Investigation Series: Volume 2 (2019) [O/4-6] by Heather Graham
- Harrison Investigation Series: Volume 3 (2019) [O/7-9] by Heather Graham