Madeline deWinter is an agent with DIAL.
Temporary agent, as she is reminded more than once and never in a pleasant voice. She is not an official operative with the organization but rather on loan to them for one specific job but that job will turn out to be a lot longer than anyone expected.
As to what DIAL is, that remains a mystery to me. It does not appear to be an acronym, at least if it is one the breakout of the letters is not in any of the adventures I have read. It is referred to at least once as "the department codenamed DIAL" and mention made of it being an offshoot of MI6. It is run by a small balding man "dressed as always in a finely-tailored black suit, white shirt and red bowtie. Gold half-round spectacles gave him a slightly caricatured look, but those who crossed him knew only too well there was nothing amusing about DIAL's commander-in-chief." It is also quite covert in nature and "not even the metropolitan police knew DIAL existed."
Back to deWinter, she was temporarily seconded to DIAL to help by going undercover to get friendly with a target. This was surprising to her because deWinter's main purpose in life was to kill. As she puts it, "My name is Gerard deWinter, and I'm a cold heartless human being. There are reasons why, but I freely admit to my shortcomings. I don't have feelings like other people do, so I'm a safe bet for the job... guaranteed not to get involved." She adds elsewhere, "I didn't have much experience when it came to high emotion. Splashing around the deep end in the pool of life was the other side of the universe for me."
And yet for reasons she cannot understand, this 36-year-old operative is picked to befriend an alien terrorist named Zana, one of a team of 7 in the cell. DIAL had identified each member (how was not revealed) but they had yet to determine what the purpose of the cell was; if it was an act of terrorism, what was the target?
Once deWinter did get close to Zana, and she to her, their lives would never be the same and the fate of the world would truly rest on their shoulders.
Note: it is important for anyone reading this synopsis and considering reading the series to read My Comments below as well as checking out the companion series .