Coughlan brings her own radiance to Joy, her beautiful round face and bright blue eyes shimmering with tears, her hair a halo of gold, framed by a bright red beret and matching jacket. Visually and emotionally, she is a shining symbol of the season, its warmth, yearning, and heartache. And in the end, she is the star this episode demanded.

There's a new companion, an old enemy and a breakneck journey through time. Here's how to watch "Doctor Who Christmas Special: Joy to the World" from anywhere.