WATERSTONES THRILLER OF THE MONTH AUTHOR: 'Britain's Patricia Highsmith' (Sunday Times)Discover the original psychological thriller as a sleep-deprived young mother struggles to stay sane. 'A lost masterpiece.' Peter Swanson'Brilliant ... Such clever, witty writing.' Elly Griffiths'Fremlin packs a punch.' Ian Rankin'Splendid ...Got me hooked.' Ruth Rendell'A slow-burning chill of a read by a master of suspense.' Janice Hallett'The grandmother of psycho-domestic noir; Britain's Patricia Highsmith.' Sunday TimesLouise would give anything - anything - for a good night's sleep.Forget the girls running errant in the garden and bothering the neighbours.Forget her husband who seems oblivious to it all. If the baby would just stop crying, everything would be fine. Or would it? What if Louise's growing fears about the family's new lodger, who seems to share all of her husband's interests, are real?What could she do, and would anyone even believe her?Maybe, if she could get just get some rest, she'd be able to think straight . . . WINNER OF THE 1960 EDGAR AWARD FOR BEST MYSTERY NOVEL'Barbara Pym with arsenic.' Clare Chambers'Sinister, witty and utterly compelling.A genius.' Nicola Upson