Grisenko, The Doctor and others in “Cold War”

We were drilling for oil in the ice. I thought I'd found a mammoth.

It's not a mammoth.

No.

What is it, then?

It's an Ice Warrior! A native of the planet Mars. And we go way back. Way back.

Martian? You can't be serious!

I'm always serious. With days off.

Doctor.

Just keeping it light, Clara. They're scared.

They're scared? I'm scared!