In this by-the-numbers thriller, bad guy turned hero Sean Dillon becomes entangled with a mysterious and indiscriminate terrorist group known as ""January 30."" Dillon (On Dangerous Ground, 1994, etc.), who once was an IRA hit man, is a bantam Superman as usual, casually walking into a death trap he tricks his foes into setting up just so that he can ""draw their fire."" His superior, Brigadier Charles Ferguson, and his partner, Detective Chief Inspector Hannah Bernstein, play their familiar roles (stolid and plucky, respectively). It helps that the villains of the piece are somewhat interesting. Rupert Lang, British Under Secretary of State for Northern Ireland, has been a Russian spy for several years, together with his former Cambridge lover, professor Tom Curry. They and their control at GRU (the post-Soviet Russian Military Intelligence Agency) created January 30 to use as a cover-up for murders they carry out in their effort to create chaos in the West. The killers of January 30 aren't picky, and they don't leave ideological footprints. They hit Israelis and Palestinians, Protestants and Catholics, Americans and Russians. Renowned actress Grace Browning (the ""angel"" of the title) is relatively new to the group, driven there by fate and by demons resulting from a childhood tragedy. January 30 secretly saves Dillon's life in Belfast, eager to have him pursue a lead that will disrupt the machinations of the rival KGB in Beirut. Grace later kills a visiting American who is under Dillon's protection and subsequently has a second American, a prominent US senator visiting Ireland to aid in peace negotiations, in her sights, setting up a grand and melodramatic finale. Let it be known that all of Higgins's trademark weaknesses are evident throughout -- plodding prose, awkward and repetitive exposition, superficial characterization. But so what. The formula is tried and true, and it works.