I’ve only read the first book of the series, Wild Card, as part of a Heroes ans Heartbreakers read-along, and I quite liked it. Nighthawk makes me want to go forward in the series, at least to the fourth book, which is the one actually about Travis and Lillian (the second one is about the case they discuss in the short story, but it’s another member of Elite Ops who handle it). I really liked the atmosphere Leigh had written in that short story, and well, secret agents are one of my favorite things, so I’ll probably dive into the rest of the series soon!