Watch out for the flying TARDIS! "Doctor Who" is filming on location in London for the 50th anniversary special.
Matt Smith and Jenna-Louise Coleman were seen on location in Trafalgar Square and plenty of bystanders were there to capture it.
The duo will be joined by former stars David Tennant and Billie Piper for the special and one Tumblr user may have captured a meeting of the two Doctors.
BBC released two teasers, which you can check out below.
This one features the stars on location in London:
And the second features the character of Strax and current "Doctor Who" star Matt Smith filming a stunt in London with the TARDIS.
"Doctor Who" airs on Saturdays, 8 p.m. ET on BBC America.