2 years ago, Elizabeth Keen could say her life was normal. She had a loving husband and was going to try and adopt a child just as she had been adopted. However, your life is a far cry from normal when you work for the FBI.
Now, you could say Liz doesn't know what to do. What with her mysterious past with a man on the FBI's most wanted list, her bosses friend being a corrupt slimy jackhole and every case bringing about different questions and less and less trust toward the man you used to go to for help. You know you have it rough, when your ex-husband, who happens to be a spy, is the only one you can trust.
Why does he stay? He's a free man, he doesn't exist. Why does Tom Keen stay when he could go anywhere in the world? Nobody even knows if his real name is. So the real question is, why does he stay? Some may say it's because it's the unexpected play, the Feds wouldn't expect him to stay, but it's for a different reason entirely, and Reddington knows the reason. It's simple. Liz.