(nowmagazine.co.uk ) - Jude Law has signed up for a new movie - starring his ex-fiancee Sienna Miller .
The pair called off their engagement in 2005 after the actor had an affair with his children's nanny.
But they will be reunited for Guy Ritchie 's flick Sherlock Holmes.
Jude, 35, will be sidekick Dr Watson, but it is not known what role Sienna, 26, will play.
Robert Downey Jr, 43, has taken the lead role.