Hm. Have you read the Anthony Price cold war books? I've often recommended them as having non-stupid plots and non-stupid characters. The main character, David Audley is a historian rather than an archaeologist, but I think there are one or more other characters who are an archaeologist, and the plots often involve excavating something.

And sometimes the historical mystery is relevant and sometimes its fabircated, but it's always "knowing about what happened" rather than "following ancient secret instructions..." :)