It was to be a most secret operation known only to a few.

Not the least of them would be to keep the entire affair a secret operation.

But some investigators and members of Congress still wonder whether there were other such secret operations.

The events of the affair involved two separate secret operations.

This latter plan was to use the money to finance secret operations.

The secret operation followed a long period gathering information on criminals in the town.

At best, three hostages were freed during the 18 months the secret operation was in effect.

How secret operations changed the course of the war.

Of one thing only was she certain; that Bob had intended to conduct this secret operation without her knowledge.

The novel is filled with such metaphors for its own secret operation.