Rachel McAdams and Robert Downey Jr Filming Sherlock Holmes in London Pictures

Rachel McAdams laughed between takes on the set of Sherlock Holmes: A Game of Shadows in London today. She was joined by her costar Robert Downey Jr., who was almost unrecognizable in a clever disguise, and the film's director Guy Ritchie. The trio are working on reshoots for their upcoming sequel, due out Dec. 16, though there was no sign of the movie's other leading man, Jude Law. Robert recently wrapped his role as Tony Stark in The Avengers and shared the exciting news that his wife Susan Downey is expecting their first child early next year. Meanwhile RDJ's not the only one expanding his family, Guy became a new dad again on Sept. 5 when his girlfriend Jacqui Ainsley gave birth to a son.