Go behind-the-scenes of episode 3 of ‘Doctor Who’ Series 9, “Under The Lake.” Warning: May contain spoilers if you haven’t watched the episode yet!

Water, water, everywhere:

Filming an underwater base on dry land is no easy feat – cast and crew tell us how!

Becoming a Ghost:

How do you become the scariest ghost on television? Actor Colin McFarlane explains!

Steven Moffat on the Sonic Shades:

The screwdriver is gone… long live the shades! You can make anything a bit ‘sonic’!

Cass & Lunn:

Sophie Stone and Zaqi Ismail talk about their characters.

The Fireball:

Special Effects Supervisor Danny Hargreaves explains how he achieved the fireball effect.

Synopsis:

When an underwater base comes under attack, the Doctor and Clara must save the frightened crew and defeat an impossible threat. But what is behind these terrifying events? And can they really be haunted by ghosts?

Cast: Peter Capaldi and Jenna Coleman.

Guest cast: Colin McFarlane, Sophie Stone, Zaqi Ismail, Morven Christie, Arsher Ali, Steven Robertson, Paul Kaye.

‘Doctor Who’ Series 9, Episode 3 “Under The Lake” airs October 3rd, 2015 on BBC America at 9pm.