Dead in THAT Beach House: A Senior Sleuths Mystery

Once we had arrived in the Hamptons, settled in and I felt comfortable, I began to add small amounts of poison to the evening cocktails. It was from the oleander flowers. I had planted them carefully behind the barn in Ames. After only weeks, they were falling ill, listless, crying to go back to Ames. They felt too sick at the beach house. It was simple.
I know you must think I’m a monster. But, really, they felt very little when I strangled them to death thanks to the poison in their system. When they were dead, I filled my library with books about murder and witchcraft. The note I leave for whomever might find them might explain what happened...

The Senior Sleuths, Dick and Dora Zimmerman, much like Nick and Nora Charles from the Thin Man series, and their cozy group of interesting, quirky friends take on crooks and murderers while dealing with an outrageous case of elder abuse.

And in the end:
“Shall we say invitations are mandatory?”
“Absolutely, dear. We wouldn’t want anyone to miss the fun”
“They’re either belligerent, arrogant, or simply annoyed,” Zero whispered to Cloud as the so-called guests arrived. They were all murderers and those who had committed crimes against the elderly.