|It happened just like this.|
Plan A: Beg manly friend Dave to come over and kill spider
Plan B: Whimper. Gingerly pick up box by corner and transport downstairs, watching the spider for any signs of wanting to leap out onto my face, and fling the whole thing into the yard while making high-pitched noises of bravery. Run back upstairs and watch developments from the window. Hope spider doesn't eat Steve, the neighbor's cat.
Conclusion: Thank God Dave answered his text messages and is a tolerant human being. I didn't have to attempt Plan B, which is good because I wanted to die just thinking about it.