Overview
Orbiting a quiet backwater planet, the massed forces of the universe's deadliest species gather, drawn to a mysterious message that echoes out to the stars. And amongst them, the Doctor. Rescuing Clara from a family Christmas dinner, the Time Lord and his best friend must learn what this enigmatic signal means for his own fate and that of the universe.
| Actor | Age then | Age now | |
|---|---|---|---|
 | 31 | 42 | |
 | 27 | 39 | |
 | 55 | 67 | |
 | 26 | 37 | |
 | 52 | 64 | |
 | 35 | 46 | |
 | 52 | 63 | |
 | - | - | |
 | - | - | |
 | 46 | 58 |