Kenneth Branagh's Hercule Poirot returns for a third time in the franchise, but does A Haunting in Venice have a post-credits scene teasing another murder mystery? The third entry in the series adapts Agatha Christie's book Hallowe'en Party as a means to pull Hercule Poirot out of retirement. The master detective finds himself attempting to solve a murder at a séance and grappling with the possibility of supernatural forces at play. It proves to be another twisting and unexpected mystery for Branagh's character to solve, with a potential A Haunting in Venice post-credits scene having the ability to tease his future.

https://screenrant.com/haunting-in-venice-post-credits-scene/