Falsity
His old colleague and supposed friend met him at the hatch. His colleague knew why he was there, to pinpoint the location of the signals that directed the drones to attack the USA.
As Nelson looked into the eyes of deceit his colleague admitted he was the one directing the traitorous attack.*
He told them what they wanted to know. He was glad to. Their promise of payment was exactly what he wanted in exchange for betraying his country. He didn't want money, a new identity, or a new home. He wanted revenge. He always knew that if he got his revenge he wouldn't need anything else. He never expected to get away with what he intended to do. They agreed to all those things in addition to the key item though seeing as they would never understand someone giving up the information they needed for less than living happily ever after in a new country with a new name, a new face and lots of new money. He didn't kid himself that he would ever use those concessions but they were arranged — just in case. They got what they wanted. It worked. They got aboard Seaview and were able to commandeer her. That's what he did; he gave them the information they needed to take control of the Seaview. Now they would give him what he wanted, the opportunity to get his revenge. It had all been arranged now. Once he had revenge he would be satisfied.
* The Machines Strike Back