Seal the tunnel! It shall become their tomb!

Together with Ticon and Sarah-Jane, the Doctor is travelling at fantastic subterrainean speed aboard the hijacked Dalek drilling vehicle.

As the incredible machine noses deeper and deeper beneath the surface of Ercos, the Doctor voices a terrible theory...

If I'm not mistaken, it's all a matter of monstrous revenge!

Sent to the planet Ercos by the Time Lords, the Doctor and Sarah-Jane find a world under Dalek control.

The time travellers' escaped Klim friend, Ticon, tells them about the Dalek mine and a strange drilling machine that can carry a crew below ground.

On their way to the Dalek camp, they meet up with Luco, who also tells of escape.

But unbeknown to the Doctor and his friends, the treacherous Luco is leading them into a Dalek trap...

They walk into our trap! The Klim slave has served his purpose well...

After helping Ticon the Klim to escape, the Doctor and Sarah Jane are told about the Dalek mine and the strange drilling machine that can travel underground. While the Doctor puzzles out their next move, he is unaware that the Daleks have made an ominous discovery...

The TARDIS! So the arch enemy of the Daleks is near!

Drawn to the planet Ercos by the power of the Time Lords, the Doctor and Sarah Jane discover the awesome presence of the Daleks. When the Daleks chase an escaping Klim and leave him imprisoned in a pit, the Doctor and Sarah Jane attempt to drag him out knowing that the Daleks will soon return with a collection vehicle. Even so, they struggle on...