PANIC! at the apartment complex

So this week I’m feeding a friend of mine’s two cats in her apartment. One of them, named Killer, is very outgoing and is always right at the door when I come over to feed them. The other one, Newbie, is much shyer, but she usually comes out too when I come to feed them. Today, however, it was just killer at the door when I came in. “Thats fine,” I thought. “Newbie will come out when I start putting the food into the bowls.” However, when I started putting food into the bowls, there was still no Newbie.  So I started looking through the apartment for her; its not a very big one.  I grew more and more nervous the further along that I went.  Once I looked under the bed and couldn’t find her,  I really started panicking.  So I ran outside and did a loop around the apartment building; maybe she had somehow gotten out, even though I was sure I had locked the door and it had been locked when I got back this morning to feed them.  I came back inside and grabbed a bag of treats and started rustling it; that usually brings cats right out.  I did it all over the living room, and then sat down on the bed and did it some more.  And then who do I see slinking out of the kitchen but Newbie. Relieved.  But where the heck had she been hiding that whole time?