Tic-Tac-Terror is the 74th title of the Hardy Boys Mystery Stories, written by Franklin W. Dixon.^[1] It was published by Wanderer Books in 1982.

In this book the Frank and Joe Hardy are asked to investigate a mystery involving a world-famous spy from HAVOC, an international network of terrorists, who wants to defect to the U.S. Frank and Joe know the spy as "Igor”.

Also a million-dollar emerald from South America has vanished. Joe and Frank think “Igor” was involved. Their only clue is mysterious symbol in shape of tic-tac-toe. The game lead to a building that is run by the U.S. government. The building has a bomb and the Hardys are trapped in a deadly game of tic-tac-toe.