The Turn of the Key - Ruth Ware

It was hard to believe that I had ever mistaken it for a regular garden. Now that I knew its history, the warning signs were everywhere. Fat, black laurel berries, the thin needles of yew, straggling patches of self-seeded foxglove, clumps of nettles, which I had taken to be weeds when I first entered the garden but which, I now saw, bore a rusted metal tag dug deep into the earth, labelled Urtica dioica.

 

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Put a name tag with its latin name in front of a nettle and all of a sudden it becomes the most deadly plant in the poison garden. Or Rowan is such a doofus that she doesn´t know what a nettle actually is. Gosh, this book is bloody stupid.