Jack did not sleep well that night. He couldn't. He woke up about every hour or so and, having checked to see if there were any signs of life from Kevin on his phone, fell into a restless slumber again. He knew that at this hour Kevin should already be asleep, and even if he was working, he certainly thought it was too late to contact Jack so he didn't. That idiot had no idea how his guy was getting anxious. There are situations where a phone call in the middle of the night is more wonderful than the most beautiful sleep and the most well-deserved rest.
Only, Kevin probably didn't realize that Jack was so anxious. After all, he had warned that he would not return home meaning that he would be busy. He gave Lambert all the necessary data so that he wouldn't have to worry. Was there a problem in something? It was in situations like this that Jack disliked the fact that he was meeting with a scientist.