The Moon Comes Over the Tower

 is a quest in Fallout: New Vegas.

Quick walkthrough
Use the terminal upstairs and to the left on the main entrance into the Lucky 38. Bar section.

Detailed walkthrough
As you enter the Lucky 38 Casino turn left and head up the stairs to the V.I.P. Lounge. The terminal you need is behind the bar. Once you try to access the terminal it will give you an option to bug the network. After you choose this option and head back outside. Emily should be at the bottom of the stairs. If not try immediately to the left near the gate to the next part of the strip.