SEASON PREMIERE: Fans of the PBS Mystery series just lost David Suchet as Hercule Poirot for good – but only a few months later, get to enjoy the return of another famous Agatha Christie sleuth, the prim but observant Miss Marple. Julia McKenzie returns for another small sampling of Miss Marple mysteries, starting with A Caribbean Mystery, in which a planned vacation turns into an unplanned murder investigation – involving the suggested element of voodoo. Check local listings.