Tonight's Doctor Who delivers a double dose of Westcountry delights for fans as the cult BBC series was filmed in Charlestown – and stars Devon's own Lily Cole.

The episode was shot on location in the Cornish port this February, and sees the Tardis marooned on a 17th-century pirate ship.

Torquay-born supermodel Miss Cole makes her debut in The Curse of the Black Spot, playing a beautiful sea monster called Siren who terrorises the Doctor and his companions.

The series-six episode features plenty of swashbuckling action, with the Doctor – played by Matt Smith – and his assistant Amy – swinging from ropes onboard the ship and fighting space pirates with cutlasses.

Doctor Who is Miss Cole's latest cameo after starring in St Trinians in 2007 and The Imaginarium of Doctor Parnassus in 2009. She also has forthcoming roles in There Be Dragons and The Moth Diaries.

Mr Smith, 28, said: "Lily was wonderful. She turns in a great performance – and she was studying for her finals at Cambridge at the time."

Large crowds gathered to catch a glimpse during filming on February 1, when the harbour was completely taken over by crews and technical equipment.

Louise Hancock, a waitress from St Austell, went along to watch. She said: "It was really impressive – there was a tall ship in the harbour which was surrounded by floodlights and camera rigs. You got the feeling the special effects were really going to make it something extraordinary.

"I felt sorry for the crew and cast because it was a bitterly cold February day – whenever they could they pulled on big hats and scarves."

Charlestown has been used numerous times over the years for film and television productions, including the latest version of Alice in Wonderland, The Eagle has Landed, Frenchman's Creek, The Onedin Line, The Three Musketeers and Rebecca.

The Curse of the Black Spot, which also guest stars Downton Abbey actor Hugh Bonneville, airs tonight at 6.15pm on BBC1.