Delphiniums and Deception

Locked in with a killer. Arranging flowers is the only way out.
When Fergus tells Diana he's taking her on a flower arranging retreat for her birthday, she should have been more suspicious.
Especially when he announces that he's coming with her.
After discovering the whole truth about the retreat, Diana is still considering how to murder Fergus . . . when one of their fellow flower arrangers is found dead-stabbed in the back with a mystery weapon.
With the retreat on complete lockdown, Diana and Fergus have a mystery to solve that wasn't part of the itinerary.
Will they find the killer before the clock runs out?