Sherlock, Series 1

[Examining Brian Lukis's apartment]

Sherlock:
Fourth floor. That's why they think they're safe. Put the chain on the door, bolt it shut. They think they're impregnable. [spots the skylight] They never consider for a moment there's another way in.

DI Dimmock:
I don't understand.

[Sherlock grabs a table, balances a chair on it and climbs up on it]

Sherlock:
We're looking for a killer who can climb.

DI Dimmock:
Wh-what are you doing?

Sherlock:
Clings to the walls like an insect. That's how he got in.

DI Dimmock:
What?

Sherlock:
Climbed up the side of the walls, ran along the roof, dropped in through this skylight.

DI Dimmock:
You're not serious. Like Spider-Man?

Sherlock:
He scaled six floors of a Docklands apartment building to kill Van Coon.

DI Dimmock:
Hold on.

Sherlock:
That's how he got into the bank: he ran along the roof and onto the terrace.