In the pulse-racing first installment of the On the Edge series, a criminal psychologist teams up with a former marine on a deadly wildland mission. Not even their hearts can stay out of harm's way.

In the swamps of East Texas, alligators aren't the only danger lurking in the shadows.

After a young woman is brutally attacked on a popular hiking trail, the evidence points to the notorious Black Cat Stalker. The town of Skull Hollow enlists Dr. Mia Frost to provide a psychological profile and assist in the investigation.

When another person goes missing, Mia partners with Easton Crew, former marine and current CEO of a tactical tracking company. Both Mia and Easton are stubborn, strong-willed, and independent, but neither can deny the smoldering attraction between them.

As professional lines blur, Easton starts to question Mia's motives and worries she's getting too close to the investigation. The mystery begins to unravel, but so does Mia's mental health as the clues dredge up her own haunted past.

It soon becomes evident that things aren't as they seem ... and people aren't always who they say they are.