Power cut

I was told this story last night by two amused parents: mum was in the kitchen and her nine-year-old was upstairs getting ready for his bedtime story. There’s a power cut, and because they live in the back of beyond that means the house is plunged into absolute darkness. As mum tries to find a torch, there’s a plaintive voice from upstairs:

Boy: Mum? Mum?
Mum: It’s okay! It’s just a power cut – I’m coming!
Boy: Mum? Where are you?
Mum: I’m in the kitchen. I’m just getting a torch and then I’ll come and get you.

There’s a pause.

Boy: Mum?
Mum: Yes?
Boy: Where am I?