What is that smell?

Firstly--bravo for reading this, after a title like that.
Secondly--No, I haven't had the baby yet.

(On with the show!)

It's been raining for about 17 hours now, and the humidity in the house is at 75% (according to the hygrometer--which I'm not sure is actually working properly, it's been dropped so many times). And our computer room smells like a cross between a wet dog, cheap plastic toys, and mildew. I'm sure it's all mildew, seeing as how we have neither dog nor any plastic toys.

I think the plastic toy association is because when I was younger (read: 8 years old), our family lived in a rental home with a horrendous mildew problem in the basement. The basement that became, by default, the playroom for my younger brother and I. This was the same house where my brother earned the moniker of "Buckethead", due to his tendency to wear a bucket on his head as a helmet whenever he played G.I. Joe. He claims no memory of this activity, even though we've got the photos to prove it happened.

Back to the smell--I fear there's nothing I can do about it. I can't open the windows to air the room out, as it is supposed to continue raining for the next 4 days. And I don't see any evidence of mildew; so attacking the source isn't an option. Also, I really don't want to be wielding toxic chemicals in my home when there's a baby on the way.

Perhaps I should just invest in one of those respirators that look like something out of a low-budget sci-fi film...Then I could call myself "The Intrepid Pregnant Explorer of the Western Stench".