Tic-Tac-Terror is the title of a Hardy Boys Digest novel, written by Franklin W. Dixon

Franklin W. Dixon

Franklin W. Dixon is the pen name used by a variety of different authors who wrote The Hardy Boys novels for the Stratemeyer Syndicate...

. Sometimes it goes by the number of 74 in the series, a continuation of the original novels, and sometimes as the 16th, as it is the 16th published by Simon & Schuster

Simon & Schuster

Simon & Schuster, Inc., a division of CBS Corporation, is a publisher founded in New York City in 1924 by Richard L. Simon and M. Lincoln Schuster. It is one of the four largest English-language publishers, alongside Random House, Penguin and HarperCollins...

 after Grosset & Dunlap

Grosset & Dunlap

Grosset & Dunlap is a United States book publisher founded in 1898.The company was purchased by G. P. Putnam's Sons in 1982 and today is part of the British publishing conglomerate, Pearson PLC through its American subsidiary Penguin Group....

 lost rights to publish new Hardy Boys books in 1979.

Summary

In this book the Hardy boys (Frank and Joe) are asked to help stop a world-famous spy who works for the HAVOC, an international network of terrorists, 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.