 When Poirot examines the hotel register for signatures of previous  guests, he discovers the names of several international celebrities  during the 1930s, including Cole Porter (qv), whose music is  featured in the film; Ivor Novello (qv);  Maurice Chevalier (I) (qv); Fred Astaire (qv) and his sister  Adele Astaire (qv)); Charles Chaplin (qv); and possibly  Marlene Dietrich (qv). An entry listing a home address is listed  as Berlin, although the signature is illegible aside from the  capital M and D). The register is likely a private joke by the  filmmakers since it appears on