AKA A Quiet Place to Kill (also known as Paranoia)
An early-ish Lenzi thriller has Helen (Carole Baker) who is a racing driver and after being in a crash is invited to stay with her ex-husband Maurice (Sorel) in his villa in Spain.
Upon arrival she meets his new wife Constance (Proclemer) who actually sent the telegram. She is older but very rich and it soon becomes apparant she hates Maurice and intends to recruit Helen in murdering him - as Helen already had one try earlier on.
A plot is hatched but as Helen is still sexually obsessed with Maurice it goes wrong and its Contance that gets killed. The lovers think they have got away with until Contances teenage daughter turns up - then things get really complicated...
Shot in stunning locations on the Spanish coast it really captures the beautiful idle rich all seething with sexual jealosy with loads of Sixties camera flourishes and if by the end its one twist too many - but always with Lenzi it grips throughout - 4/5