what’s being filmed at Somerset House (15 Jan 2025)

i was walking past Somerset House just 20 minutes ago while returning from uni and spotted a massive christmas tree in the centre of the courtyard, the entrance barricaded off, lots of staff in hi vis vests and signs which said that filming was in progress. obviously i was curious so i asked one of the volunteers at the entrance, he said he's not allowed to tell people the title of the movie, but it is a film and not a tv show. is anyone here an insider or somehow has access to the information? i'm just nosy and wanna find out what the movie is :)