The following version of this book was used to create this study guide: Harper, Jane. Aaron Falk Series #2: Force of Nature. Flatiron Books, 2018. Kindle.

The second novel in the Aaron Falk series begins with a prologue in which four women came out of the bushland after a corporate retreat without one of their coworkers, Alice Russell. In the first chapter, Aaron Falk, an agent with the financial crimes unit, got a call from his new partner, Carmen. She told him that Alice Russell, a woman they had been working with in order to secure documents that proved her company was wrapped up in money laundering, was missing. Because Alice disappeared on a corporate retreat that involved her boss and his sister, and because she had tried to call Falk from the bushland just hours before she disappeared, Falk and Carmen go down to the Giralang Ranges to help investigate what had happened. As they drive toward the bushland where a captured and deceased serial killer named Martin Kovak attacked several women 25 years ago, Falk and Carmen read the case file and see that Alice had been on the retreat with her boss, Jill Bailey, her assistant, Bree, her assistant’s twin sister, Beth, and Lauren, the strategic head of forward planning.

The four women had come out of the bushland bruised and bloody, and Bree had been bitten by a snake. The chapters alternate between the narrative present, in which Carmen and Falk investigate Alice’s disappearance, and a rotating perspective of the four living women’s time spent on the retreat, starting on Thursday afternoon and going up until Sunday evening. On Thursday night, the men’s group, which was scheduled to take a different route through the bushland, surprised the women and spent the night drinking with them around the bonfire. Daniel Bailey, the executive of BaileyTennants, pulled Alice aside and had a tense conversation with her. After this, she tried to call her daughter and convince Jill Bailey to let her go home, but her phone, which she had snuck into her backpack, would not work and Jill would not let her go. On Friday, a hungover Bree navigated the women down the wrong path. Instead of turning around when they realized what had happened, they decided to take a shortcut through the bush and ended up more lost than ever. After losing their tent poles and the gas cannister in a river, the women spent the night in the wet bushland, exposed and hungry. On Saturday morning the women were grumpy and hungry. When they took a break from walking towards what they hoped would be the road, Beth took out a cigarette to smoke, and Alice grabbed her whole pack and threw it into the bush because she was sick of the smell. Beth went to go retrieve the cigarettes and found a cabin that once belonged to Martin Kovak. Alice wanted to continue forward, but Jill and the others decided it would be better to stay and wait for help. Carmen and Falk left the bushland and returned to Melbourne with Lauren. They tracked down Daniel Bailey, and discovered that his son had posted explicit photos of Alice’s daughter, Margot, on the internet. Daniel had told Alice about the pictures on Thursday night, and after hearing the news, Alice was desperate to see her daughter. Carmen and Falk then went to Alice’s house and spoke with her daughter, who was hiding from her father. They arranged for her to stay with Lauren, whose daughter Rebecca was suffering from an eating disorder brought on by an incident of bullying involving her weight the previous year. Carmen and Falk had a romantic dinner together, despite the fact that she was engaged, and then they received a phone call that the rescuers had found the cabin where the women had stayed. They drove back to the bushland and went out to see the cabin where the women had stayed on Saturday night. They had built a fire outside and had a few moments of solidarity, but then Alice said that she was going to leave in the morning with her cell phone, which was the only cell phone they had.

The women got into a physical fight over the phone, and Jill ended up with the phone. They all went to sleep, and in the night, Alice stole her phone back and went out into the bushland to strike North for the service road. A nameless someone watched her leave and then followed her. Falk and Carmen went back to the lodge, but then the Sergeant called them and told them that Alice’s body had been found, right next to a tree with a snake inside of it, which suggested that Bree had something to do with it. Carmen and Falk detained the twins and learned that Bree had found Alice’s dead body, but she had hidden it because she thought her sister, who suffered from addiction, had killed her as a form of revenge after the previous night’s violence.

The watcher was revealed as Lauren, who spotted Alice leaving with the phone and tried to stop her. Soon the argument exploded as both women’s daughters were brought into the mix. Margot had been the one to bully Rebecca, just as Alice had once bullied Lauren. The women insult each other’s parenting, and then Lauren physically assaulted Alice. They fell to the ground and Alice hit her head. She was not bleeding, so Lauren thought that she was fine, and left her dazed but conscious to do whatever she wanted to do with her phone. When Lauren woke up to Bree’s screams from the snakebite and the women decided to leave, Lauren checked for Alice in the spot where she had left her, but she was gone, so Lauren assumed she had walked off. Falk and Carmen uncovered Lauren’s role in the matter when he discovered Lauren’s bracelet wrapped up in Alice’s jacket zipper. They ran to find Lauren, but realized she had fled to the waterfall to kill herself out of guilt. Falk managed to stall her until Carmen arrived with backup, but then Lauren jumped. Falk jumped in after her and rescued her. Carmen helped pull him out and then kissed him on the shore.