A smile can be deceptive… and that’s certainly true on the planet where the Doctor and Bill take the TARDIS this week. The pair have parked up near a sparkling space age city which is a housing development of the future that humans will be able to colonise in peace and harmony after evacuating a dying Earth.

It looks spectacular, and spotlessly clean, thanks to Emojibots – little robots with smiley faces that have been working tirelessly, with swarms of micro-robots called Vardies, to create a wondrous new settlement for new earthling arrivals. But something has gone seriously wrong, meaning any human that gets hugged by an Emojibot becomes a scorched skeleton within seconds! The Doctor and Bill soon work out why so few people are around, but taking on the small smiley assassins proves one big nightmare…

The Royle Family’s Ralf Little turns up towards the end of the adventure. He plays Steadfast, a human colonist who’s arrived at the wondrous space age city, but learns that most humans have been wiped out by the Emojibots. When the Doctor and Bill eventually catch up with Steadfast and a small group of humans, they all band together to take on the deadly robotic enemies. Steadfast has access to guns and assault weapons, but will they be of use against such an unusual foe?