The cast continues to build for Night at the Museum 3. Ben Stiller was the first to sign on, respiring his role as night security guard Larry Daley. Then came Robin Williams, who appeared as Teddy Roosevelt in the last two movies. Now, Downton Abbey star Dan Stevens has agreed to appear as living mannequin Sir Lancelot of the Roundtable.

Shawn Levy returns as director of this billion dollar franchise. This time, the action will take place in London, though no further story details have been revealed. It is known, though, that Sir Lancelot is the main villain of the movie this time out.

Dan Stevens recently appeared in the WikiLeaks drama The Fifth Estate and will next be seen in A Walk Among the Tombstones. It is believed that original writers Thomas Lennon and Robert Ben Garant are returning for scripting duties, but that has not yet been confirmed by the studio. They may have provided a first draft, but it is not known who is behind the latest polish, if anyone.