Bingowings said:

The better half is still freaked out by this even though he can't see the whole story again.

I remember seeing screecaps of the two guys releasing the gas attack when I was younger. That image scared the crap out of me. (I think it was around the time in the late nineties when they rebroadcast a lot of stories. The ones I remember the most are Genesis of the Daleks, Spearhead from Space, The Dalek Invasion of Earth, The Moonbase and Doctor Who and the Silurians. All of them made me cower behind the sofa in terror.)