The author made no effort to tell a coherent story. An FBI SA and AF corpsman(?) are trying to mold a juvenile mutual affection while chasing an escapee and accomplice. The girl K9 handler keeps losing her gun or not using it. FBI dude keeps fainting. They both are obviously trying not to catch the escapee.
I was grabbed by the first sentence as I did engineering work on H-60G rotary wing AC in 1990 for SAR and SOF applications. With NVGs and FLIR and other IR visualisation, no mammal can hide from your helicopter at night. I also camped in the TX hillcountry about 100 times, there are a few canyon walls where someone could briefly hide but 4-6 searchers could easily find everyone in the small search area they describe within a few hours. So the author is making it clear that our protagonists are incompetent and excusing them because they are lovelorn or grieving and clearly have subnormal intelligence to start with. So they are made for eachother. As usual, the dog is smarter than either.