There was this giant spider in my room. I'm afraid of spiders. I went to get something to get it with, and I came back. The spider is now missing.
Oh great. There was a big spider in my room, so I went to get something to scoop him up with (or flatten, I hadn't decided between the two yet). I come back and he's disappeared. 
user
oh oh, so now you don't know where your enemy is hiding.  Sounds scary.
assistant
It's scary and annoying because now I have to systematically check every inch of my room because I'm definitely not sleeping here with that big ol spider somewhere in my room!
user
How annoying, but would be wise imagine it jumping on you while you sleep.
assistant