Tom Clancy's Firing Point

During a well-earned break, Jack Ryan Jr runs into old flame Renee Moore in a scenic Barcelona café. But Renee is not so pleased to see him. Distracted, she says she's waiting for someone and can't talk. She promises to call him later, and sends him out onto the street. Which is when the bomb goes off.

There's nothing he can do to save Renee. But as he cradles her, she utters one last word with her final breath: 'Sammler'. 

Who did she mean? What did she know? And what trouble had Renee got herself into?