I Remember Everything. Dark and Twisty Psychological Thrillers, #3

You didn't fall. You were pushed. Stephanie Silkwood just hit her head. Hard. When she comes to, she's on the deck of a luxury cruise boat headed down the Amazon River. Stephanie remembers nothing about the moments before she fell from the second story of the luxury boat, except for one thing: two hot palms against her back before she went overboard. On vacation with her husband, Steve, and their friends Colin and Leslie, Stephanie finds herself unable to remember anything about the couple after her injury, other than who they are. When Stephanie gets her phone back, the last thing she'd been looking at was a document giving her reason to believe that Colin might have been embezzling money from the business the couples share.
Stephanie brings this to Steve's attention and he seems unbothered, unwilling to see what's so apparent to his wife. Tensions rise the deeper the boat travels into the jungle. Stephanie must navigate not only the simmering discord between the couples but also her memories that are bubbling just below the surface, ready to return at the most inconvenient time. As she gets closer to discovering who pushed her from the boat and why, Stephanie and the others go deep into the jungle on an overnight adventure that brings their relationships to the brink. And not everyone will survive the night.