It's a long series and still one more book to go. Despite the name, it's not Heller we read about here, though he is, albeit, a very important part.
Our protagonist is the tall, charming, generous, and kindhearted Tilly (Matilda) Chalmers who out of desperation joins a security agency headed by the handsome Heller. And that is precisely when her life completely changes (whether for the best or worst, that is highly debatable). In fact, the things that happen to her from the moment she sets foot in their warehouse styled office, should have been hints enough for her to realize how her life was going to turn.
Throughout the series, we find Tilly going on all kinds of assignments; meeting mostly crazy, dangerous, though sometimes nice, people; juggling her personal and professional lives; and all this while, trying to figure out the mysterious Heller.
Heller is an enigma. He absolutely refuses to share any information about himself or his past, though from others we come to know bits and pieces about him. He can be sweet, caring and understanding when he wants. But mostly he is extremely insensible and unemotional, hardcore practical and business-minded. Tilly has to suffer due to some of Heller’s decisions. He can also be a dictator at times. In “Heller’s Regret”, he is more absent than present, leaving Tilly alone to face all the problems that come with being a security officer and then some. In other words, feelings about Heller can get pretty mixed.
Special mention should be made to Daniel and Nick who are among those few people always there for Tilly.
The whole series is interesting, adventurous and more than enough to keep one entertained in Tilly Chalmers’ life for a long time. The level of danger increases with each passing novel and Tilly is transformed from being a carefree, lightweight, protected girl to a fiercely independent, brave woman who refuses to back down.