cover story 
noun
1A magazine article that is illustrated or advertised on the front cover.A front page cover story or a feature spread in a magazine helps boost exposure, thereby boosting potential sales....
- The article is the cover story of the Washington Post Magazine this week.
- Time magazine devoted its cover story to the subject two weeks ago.
2A fictitious account invented to conceal a person’s identity or reasons for doing something.The cover story and the identity documents carried by Tai and his traveling companions were quickly discovered to be false....
- He didn't want that campaign to become public, so he invented a cover story, repeated it under oath, and stuck to it on multiple occasions.
- He felt he had to invent a cover story to go around this, to make it believable.