The engineers were made to beg for info on the girl, so they might be getting some satisfaction from keeping a secret from the author in return. I know I would.

The engineers were made to beg for info on the girl, so they might be getting some satisfaction from keeping a secret from the author in return. I know I would. Give 'em a taste of his own medicine. Also, if it was a relatively simple solution, it's probably more exciting with some mystery overlaying it rather than just explaining it outright.