The two gardeners are asked by the Caldecott family to restore a grand water cascade in the grounds of their mansion-turned-health spa. Stumped by the long-decayed mechanics of the feature, Rosemary and Laura soon realise all is not well: a killer is on the loose and family ties are the motive behind a murder.
- Felicity Kendal as Rosemary Boxer (3rd appearance)
- Pam Ferris as Laura Thyme (3rd appearance)
- Ryan Phillpott as Matthew Thyme (2nd appearance)