She walked down to the edge of the river, careful not to step on any visible prints, taking photos of the ground as she went. Here the river was wide and shallow, running over large stones, sparkling in the bright sun. A popular paddling spot, partly shaded as the river ran deeper under the trees a little further down. Beyond that, it passed the cafe and continued on to the disused millpond before entering the city’s vast network of channels. Upriver, it wound its way through a good stretch of dense woodland. You could follow the path alongside the river, all the way through the woods, passing deeper through the valley as the peaks rose higher and wilder, right to the New Riverby reservoir, probably five or six miles out. That immense stretch of lake hadn’t always been there. The New Riverby was built before the first war, but before that, for centuries, the valley had been home to a thriving community, the drowned village of Selverton.

“We’ve got officers on the river path, haven’t we?”

“Yes, boss. Several, in both directions.”

Harper’s eyes were drawn to the water. On the other side of the river, the high brambles would have been impossible to breach. There were areas further up where a person could get through. Perhaps they needed to search the other bank, too.

Behind her, Atkinson approached and lowered his voice. “Sarge. The mother, she’s very distressed.”

“Well, yes. She would be.”

Harper returned her attention to the water, the large rocks and shadowed areas to her left and right.

“I mean, health and safety, and all that. I think she’s a risk.”

“To who?”

“Herself. Us. Just a risk. You saw what she was like in there. I think we might need help with her.”

“Help how?”

“I mean medical help. Just in case. I mean, if the last call she made was dealt with by Mental Health …”

Harper remembered the hospital, how Lauren had had to be sedated after what happened to her there. Atkinson was right—they couldn’t predict what she might do. She nodded.

“You do what you think, Constable. Get an ambulance on standby if it’s appropriate.”

“Yes, boss.”

The constable turned and began walking back towards the cafe, lifting his radio to summon the medics. Harper was about to follow him, when she spotted something at the water’s edge. She called the officer back.

“Give me an evidence bag. Quickly.”