robert ludlum's the bourne vendetta by brian freeman
Two years ago, Bourne knew he had to let Abbey Laurent walk away from his dangerous world. Now Abbey is back — and she’s married to a top government official. But she’s convinced someone is trying to kill her husband, and she wants Jason’s help.
Bourne follows the plot against this man into a deadly web of
conspiracy that puts them all at risk. But the deeper he descends into the violence, the more he believes that Abbey may not know who her husband really is. - goodreads