A SHORT foreword to The Landing lists some of the source materials on which Haynes Johnson and Howard Simons relied in putting together this thriller-cum-docu-mentary, but this little exercise in academic buttressing doesn't prepare one for what follows, a trip, complete with heat, confusion and terror, to wartime Washington, a chase played out in the summer of 1942.

At one level The Landing is fairly standard stuff, the good American hero pursuing the evil Nazis, growing closer, falling behind, holding our attention by those devices which E.M. Forster called the technique of "and then . . . and then."

At another level, however, the book succeeds wonderfully as a kind of anthropological look at the folkways of the big village from which the tribal chiefs of the Allied Powers conducted their war with the distant tribes of the Axis.

As one who spent most of 1942 in the red clay scrublands of North Carolina, I cannot say with first-hand knowledge that this is the way it was at the center of power, but I can say that Johnson and Simons make me believe that this is the way it was.

One of the devices they employ with success is a 1942 vocabulary in which, for example, blacks are identified as "colored people" and "Negroes." After one's first discomfort at these archaisms comes the knowledge that Washington in 1942 was the kind of place where black workers in the arsenal of democracy had to enter many parts of the arsenal through separate doors.

The most fully realized character in The Landing is a black detective sergeant, Leon Thomas, a man who tries to do an honest job within a system which has no respect for his honesty.

It is one of the virtues of this thriller that it succeeds in integrating its material about the black community into the story so that it serves the narrative, as well as informing us about forgotten and unpleasant hypocrisies that underlay the posters and slogans of the war effort.

In addition to reading their way through many more old documents than they mention in their foreword, it would seem that Johnson and Simons spent many hours in the advertising pages of the Washington papers of the summer of 1942. (Both men have been long associated with The Washington Post, though Simons now directs the Nieman Fellows in Journalism at Harvard.) There are times when the stream of evocative product names make the novel seem briefly like an old mail-order catalogue. So also there are occasional little blocks of pop history which stop the action while the authors fill in those born after 1942 and remind those born before it. But these are small sins in a fast moving and exciting book which keeps you on the edge of your seat -- despite the fact that you are likely to know that the villains didn't accomplish the things that Admiral Canaris of German intelligence ordered them to do.

There is, of course, a love story. Here, in the romance between Constance the beautiful FBI secretary and Lieutenant Eaton of Naval Intelligence, the authors do some of their best work in recalling a past age. Through the devilish clever use of a writing style which puts us back in the pages of some yellowed issue of Collier's, they weave their romantic spell. Lecherous old men are referred to as garter-snappers, seams are straightened, lovely eyes widen in surprise, and surprisingly we find that in the flatness of modern realism we may have lost as much as we gained.

Great men make extensive appearances in The Landing and those of us who were not privileged to chat with them are not qualified to say how accurate the portraits of Franklin Roosevelt, Winston Churchill et. al. may be, but in terms of the stereotypes we have accepted they work fine and fit into the plot lines provided for them.

Oddly the least successful characters are the villains, those cold-eyed Nazis, even though it is accepted by most of us that the bad guys are usually more colorful than the good, but they serve their fell purposes and come close enough to accomplishing their fell ambitions to keep us in appropriate suspense.

THERE IS a temptation to give The Landing the overall if shallow approval of "rattling good yarn," or "will keep you turning pages till the wee hours," and indeed it seems like the right sort of book for the sadly mythical hammock into which so few of us seem to manage to get during increasingly busy summers.

There is more to it than the traditional pursuit-and-shoot of the thriller genre, however. One of the beauties of this form in excelsis is that you can read it over again six months later having forgotten everything except its readability.

In The Landing there is a serious undercurrent -- the seldom examined problem of race relations in a city suddenly forced into an unwanted cosmopolitanism -- which makes it disturbing as well as absorbing. I suspect that in six months I will still remember Sergeant Thomas and his problems in defending a democracy which seemed to despise him. Heywood Hale Broun, a correspondent for CBS' "Sunday Morning," is the author of the family memoir, "Whose Little Boy Are You."