The Secret House of Death (Unabridged‪)‬

Louise North doesn't care what the neighbors think. She lets her lover leave his car just outside her house in broad daylight, telling everyone he is a central heating salesman. Still, it's a shock when she's found shot dead, covered by the equally dead body of the "salesman."

It was his third visit to the gloomy house on Orchard Drive. Each time, he parked in the same place. Each time, he carried a briefcase. And each time, Louise North greeted him at the door.... Susan Townsend was the only resident with no interest in the affair going on next door, or in the neighbourhood gossip about it. Yet when Susan finds Louise shot dead, underneath the equally dead body of her lover, it is Susan who must help Louise’s husband, Bob, to get back on his feet. But is she really a helpful neighbor or, a murderer?