The Queen's Messengers are the super-trustworthy, top-level couriers who carry important correspondence to and from British embassies around the world. So when a Hong Kong-based Queen's Messenger named Bill Marston disappears just after returning from China, Gordon Clive of MI6 is dispatched to investigate. Clive leaves London for Asia somewhat reluctantly--because he's just finally settled down (with pregnant bride Katherine) and because he's still guilt-haunted by a Communist torture-interrogation he suffered years ago in Thailand (he broke down and gave names, with fatal results). But soon Clive, ducking assassination attacks in Thailand, has figured out the basics of the disappearance: Marston must have been lured, by threats against his beloved, motherless daughter, into the custody of the KGB--who are after a message Marston was carrying. . . a message from an anonymous intelligence-source in the Thai jungle who calls himself ""Charlie Excalibur."" (According to the CIA ""Charlie"" is a US Vietnam-deserter who has information on Vietnam-era leaks to the Communists.) And although Clive manages to locate the hideout where the KGB is holding Marston, he's too late to save the daughter: she has been killed by a KGB torturer (in a grisly scene); Marston, when rescued, is in a catatonic state from his own torture; and while Marston does emerge from catatonia long enough to give Clive the Charlie Excalibur message (which he heroically never divulged to the KGB), he dies of a heart attack when he becomes aware of his daughter's death. The contents of that all-important message? The enigmatic Charlie E. has requested a face-to-face jungle meeting with Clive. So the finale is a jungle encounter Ã la Stanley and Livingston--with Charlie offering evidence of a high-placed British traitor in exchange for a new life for himself. (Also, in the process, Clive gets some information that washes away his longtime guilt.) First-novelist Duncan doesn't pace this relatively simple spy-plot terribly well: the start is slow, the revelations bunch up badly in the last 100 pages. And Clive, who kills everybody in sight and rather too easily succumbs to adultery, isn't the most appealing hero around. But the Asian locales are strongly sketched, Marston's martyrdom is grimly affecting, and this is solid, literate entertainment in the violent-but-thoughtful espionage genre.