Here's my backstory: I live on the top floor of a small building with six apartments total. I came home ready to tune into Gossip Girl last night and discovered this cute cat wandering around. Now, my first instinct was that the pet belonged in apartment three, but when I knocked on the door, there was no answer. Eeks! Worried that my new, tagless kitty BFF would find its way out onto the street never to be found again, I kept periodically checking my hallway over the next several hours and the kitty was there on my doormat until my last check before bedtime at around 1 a.m. I was totally torn the entire time: While the idealistic animal lover in me wanted to bring the cat inside (imagining North and Kitty curled up in no time), realistic PetSugar figured that inviting a strange, seemingly friendly creature into my home could likely traumatize both North and the feline. To cover all my bases, I slipped a note under the door telling them that I saw what was possibly their cat roaming the hallway but still felt horribly guilty about this lost pet seemingly determined to join my furry family. If you were in my shoes, what would you have done?