Meanwhile, several people in the area have become infected with the Darkness, attacking their friends and family.
Will and the Colonel arrive at a blue police box, which the Colonel states is the Code Blue. A man is being mugged by a teenager, and they rescue him. The Colonel introduces him as the Doctor, UNIT's former science advisor.
The Doctor explains that in a previous life, he prevented the Verulans from invading Earth, but unbeknownst to him, an entity called the Darkness was attached to the Verulan ship, and when the ship exploded, the Darkness came to Earth. It preys on darkness and anger, but for now it's contained to this one street. As the three make their way down the street, Will steps into a shadow and is engulfed with anger. The Doctor pulls him out of the shadow, and he sits off to the side, recovering, as the Doctor and the Colonel discuss how to defeat the Darkness before the sun sets.
The Colonel calls in several floodlighting rigs, lighting up the street. The Doctor can detect no trace of it.
He offers to take the Colonel and Will back to UNIT HQ.
- Sixth Doctor
- Emily Chaudhry
- Will Hoffman
- Shaun Ashdown
- Bill Ashdown
- Anna Ashdown
- Mr Goodman
- Sally Moore
- Colonel Chaudhry informs Hoffman of a Code Blue.
- The events of How You Get There, The Last Broadcast and this story take place in London on the same day.
- This story is the first in a trilogy of stories featuring the Sixth Doctor, Chaudhry and Hoffman. It comes before Incongruous Details, in Short Trips: The Centenarian, and Defining Patterns, in Short Trips: Defining Patterns.