Through the mirror, Tikki sees one of the guards look in her direction, then 
look back to his partner. They converse. One shrugs. Tikki drops the mirror,
yanks the door wide open and braces her left forearm against the inside of the 
doorway, aiming the XP-700 straight up the hall. The weapon’s laser targeting
system and optical sight have been zeroed in for two hundred meters exactly. 
She’s now taking aim at close to one-eighth that range, which changes the
geometry. Tikki’s no mathematician, but she knows certain bits of math through
long experience. She worked out the degree of error in point-of-aim a few days 
before. It’s a matter of several centimeters. She’s got the number in the back
of her mind, but what she thinks right now is almost subconscious, intuitive, 
instinctive: aim low. She knows how much lower is right by how it looks, 
how it feels.