Breaking into headquarters was child's play using the blueprint Alex had studied until he could recite it forward, backward, and upside down. He had plenty of experience sneaking around in air ducts too.
Watching for weak areas was important, as was avoiding fans. That was what the blueprint had been for.
This was an old building and the security actually wasn't that great, all things considering. There was a security checkpoint outside to complete the ruse that headquarters was a normal warehouse and there were fences to help maintain the illusion.
There wasn't a proper security system with motion sensors or anything though because of the nature of their work. Illegal hideouts can't utilize legal means of protection.
There was a security room with cameras monitoring the inside but Alex knew where each one was and how to stay in the blind spots. Having a system like that was kind of redundant when dealing with highly trained Numbers.
