secret agent
intelligence officer
intelligence agent
operative

Getting hit by a secret agent results in a game over.

As you can see in the report, he's a former British secret agent.

He appears near the end of the film as a secret agent.

One car, full of secret service agents went ahead and two cars followed close behind.

It seems he must have also been a secret Soviet agent all the time!

There will be no need for secret agents to protect me.

The fellow was a secret agent to my certain knowledge.

It was an association that would continue, with or without his secret agent.

The book is based on interviews with more than 100 current and former secret service agents.

No one was introduced as a secret agent; not even David.