The Doctor, Tom and Val arrive in Singapore, a city that is at once a hotbed of technological development and a product of millennia-old cultures. There they must face threats both technological and mystical, as ancient forces cause havoc for their own ends. While Val faces a being she would never have believed existed, Tom finds himself embroiled in shocking events at the forefront of technology, while the Doctor finds his endurance tested as he fights to save lives.

"People say silence is golden but what they actually mean is quietness. Remember that old Hollywood cliche; it's quiet, too quiet? Cliches are only cliches because they're true. Total silence is unsettling. It makes you feel uneasy. It feels wrong. That's because in between all the everyday sounds we hear, there exists a nightmare and it's here with us right now!"

Answering a distress signal, the TARDIS arrives on an isolated planet at the edge of the universe. The Doctor, Tom and Val find themselves in a deserted base. The crew of colonists have disappeared and the only evidence they were ever there is the ringing of the base alarm and claw marks on the wall where someone has fought for their life and lost.

Tom and Val discover that travel in time and space is more dangerous than they would have ever imagined. The two friends must learn to work together if they are to survive the dangers that the universe throws at them, and the Doctor must face a childhood nightmare that he thought was nothing more than a myth.