Coupled with the mysterious disappearance of a local child we hear a rumour that a baby's cries could be heard from a local cliff path, which passes above McBain's farm. This seems worth investigating, so we head out for a scenic afternoon walk.
The path itself doesn't give us any clues as to what may be happening, but we notice a figure leave McBain's farm, pluck leaves from a plant, and head back inside. It wasn't McBain, and although he may have visitors the figure's actions bear closer scrutiny.
We hang around until the evening draws in, at which point it becomes safer to sneak up to the house, grab a couple of the leaves from the bush ourselves, and get clear before being noticed. Subsequent analysis of the leaves shows them to be used in sedatives. It's still not much proof, but circumstances are getting more suspicious at each step.
'We could just set fire to the building', suggests Madame Milton.
'And recover the dead body of the missing daughter?' says Castle, pointing out the flaw in her plan.
'It's no less than we promised. And at least we'll have found her.'