Developers for Doctor Who puzzle app Legacy have announced that Eighth Doctor Paul McGann, and Sarah Jane Smith (played by Elisabeth Sladen) will be added to the game shortly.

Doctor Who: Legacy is available now for free on Google Play and iTunes

Up first is Sarah Jane Smith, who will be released on Sunday 22 December (around 10am GMT). Users will require a promo code to unlock the companion character, which will be released on the Doctor Who Legacy Facebook page, as part of their Advent Calendar.

The Eighth Doctor will follow on Monday 23 December. A guaranteed drop - as with previous Doctors - Paul McGann’s Doctor will be found upon completion of the Paradox of the Whispermen level. Excitingly, the artwork for the Eighth Doctor features him in his The Night of the Doctor costume, complete with boots, scarf and shorter hair.

This release news comes hot on the heels of their recent addition of the Sixth and Seventh Doctors as free characters.

Doctor Who: Legacy is a new free to play mobile action-RPG, where fans can play though 50 years of adventures in space and time. It is available now for free on Google Play and iTunes.