In Episode 2 of Death Valley Series 1, a rambling group led by Anne Treadway, including Yvonne (DS Janie Mallowan's mother), is walking in the Welsh countryside when they discover the dead body of a new member, Karen Barnes, near a waterfall. Although it initially appears Karen fell accidentally, John Chapel suspects murder and believes the killer is among the group. Investigations reveal Karen was new to the area and possibly involved in blackmail. John and Janie work together to uncover the truth behind Karen's death, with the episode blending lighthearted moments with darker themes of murder and revenge.

The main characters involved in the investigation are John Chapel, a detective with insight into the case; DS Janie Mallowan, who calls John out to assist; and Janie's mother, Yvonne, who is part of the rambling group where the body is found. Anne Treadway leads the rambling group. The victim is Karen Barnes, a new member of the group and the local area.

Karen Barnes is revealed to be not only new to the rambling group but also new to the local area. This raises suspicions that she may have been targeting someone in the group, possibly for blackmail. Her unfamiliarity with the area and the group members adds complexity to the investigation and suggests motives beyond a simple accident.

The scenic Welsh countryside provides a picturesque yet isolated backdrop for the episode, enhancing the mystery and tension. The natural setting of the mountain trail and waterfall is central to the discovery of Karen's body and the unfolding investigation, emphasizing both the beauty and danger of the environment where the crime occurs.

Episode 2 explores themes of trust and suspicion within a close-knit community, as the murder suspect is believed to be among the rambling group members. It also touches on secrets and hidden motives, such as blackmail and revenge. Additionally, the episode balances lighthearted social interactions with darker, more convoluted elements of crime and personal history, including Janie's fierce defense of a suspect revealing aspects of her past.