Nathan checked all calls to company lines made by any of the workers. The bomber had had permission to enter in by security.

It only meant that an insider had called him in. He had a betrayer in his company, and someone who wanted to die with the building?

It was clear no one left, so whoever had called the plumber must have wanted to be killed as well. It made little sense.

“Run it again, and run for texts. Check for yesterday. They might have made the call yesterday,” Nathan said to the programmer.

The man ran it again and raised his hands. “Yesterday, an ID Garcia Carlos called...